Static analysis tools have evolved over time to assist in detecting bugs. However, the excessive false warnings can impede developers’ productivity and confidence in the tools. Previous research efforts have explored learning-based approaches to identify bug warnings. Nevertheless, their coarse granularity, focusing on either long-term warnings or function-level alerts, are insensitive to individual bugs. Also, they rely on manually crafted features or solely on source code semantics, which is inadequate for effective learning. In this paper, we propose DeepFWI, a learning-based approach that identifies bug-sensitive warnings at a fine-grained granularity. Specifically, we design a novel LSTM-based model that captures multi-modal semantics of source code and warnings from automated static analysis tools (ASATs) and highlights their correlations with cross-attention. To tackle the data scarcity of training and evaluation, we collected a large-scale dataset of 280,273 warnings. We conducted extensive experiments on the dataset to evaluate DeepFWI. The experimental results demonstrate the effectiveness of our approach, with an F1-score 67.06% for confirming true warnings in a finer-grained manner, significantly outperforming all baselines. Additionally, to validate the practicality of DeepFWI from the perspective of developers, we applied DeepFWI to four popular open-source projects. Our approach filtered out the vast majority of warnings, while still successfully surfacing 25 true bug-related warnings that were confirmed through manual analysis.

Graph-based detection methods leveraging Function Call Graph (FCG) have shown promise for Android malware detection (AMD) due to their semantic insights. However, the deployment of malware detectors in dynamic and hostile environments raises significant concerns about their robustness. While recent approaches evaluate the robustness of FCG-based detectors using adversarial attacks, their effectiveness is constrained by the vast perturbation space, particularly across diverse models and features. To address these challenges, we introduce FCGHUNTER, a novel robustness testing framework for FCG-based AMD systems. Specifically, FCGHUNTER employs innovative techniques to enhanceexplorationandexploitationwithin this huge search space. Initially, it identifies critical areas within the FCG related to malware behaviors to narrow down the perturbation space. We then develop a dependency-aware crossover and mutation method to enhance thevalidityanddiversityof perturbations, generating diverse FCGs. Furthermore, FCGHUNTER leverages multi-objective feedback to select perturbed FCGs, significantly improving the search process with interpretation-based feature change feedback. Extensive evaluations across 40 scenarios demonstrate that FCGHUNTER achieves an average attack success rate of 87.9%, significantly outperforming baselines by at least 40.9%. Notably, FCGHUNTER achieves a 100% success rate on robust models (e.g., AdaBoost with MalScan), where baselines achieve less than 24% or are inapplicable.

Android malware continues to evolve, posing significant challenges in generalization, fine-grained detection, and interpretability for existing detection systems. Existing methods struggle to generalize to unseen malware, lack fine-grained behavioral understanding, and provide limited interpretability due to their reliance on rigid rules or the inability to recover complete causal behavior paths. To this end, we present ForeDroid, a unified and interpretable framework for Android malware detection and explanation via scenario-aware analysis. ForeDroid models malicious intent as behavioral inconsistencies within functional scenarios. It clusters semantically coherent scenarios, extracts sensitive API call chains, and summarizes them into natural language using LLMs. These summaries are embedded and compared against benign behavior distributions within the same scenario for unsupervised anomaly detection. High-risk behaviors showing strong semantic inconsistency are further interpreted by an LLM-driven module that generates fine-grained anomaly reports. We evaluated ForeDroid on two challenging tasks: zero-day malware detection and fine-grained behavior analysis. The result shows ForeDroid outperforms MaMaDroid, MalScan, DeepRefiner, and a continuous learning-based approach in zero-day malware detection under the temporal-split setting. Besides, ForeDroid achieves an F1-score of 0.94 in fine-grained behavior detection on the manually annotated GPMalware dataset, surpassing ProMal. Our results demonstrate ForeDroid's ability to bridge low-level call graph analysis with high-level semantic reasoning, making it a practical, interpretable solution for malware detection.

Deep Learning (DL) has achieved significant success in socially critical decision-making applications but often exhibits unfair behaviors, raising social concerns. Among these unfair behaviors, individual discrimination-examining inequalities between instance pairs with identical profiles differing only in sensitive attributes such as gender, race, and age-is extremely socially impactful. Existing methods have made significant and commendable efforts in testing individual discrimination before deployment. However, their efficiency and effectiveness remain limited, particularly when evaluating relatively fairer models. It remains unclear which phase of the existing testing framework (global or local) is the primary bottleneck limiting performance. Facing the above issues, we first identify that enhancing the global phase consistently improves overall testing effectiveness compared to enhancing the local phase. This motivates us to propose Genetic-Random Fairness Testing (GRFT), an effective and efficient method. In the global phase, we use a genetic algorithm to guide the search for more global discriminatory instances. In the local phase, we apply a light random search to explore the neighbors of these instances, avoiding time-consuming computations. Additionally, based on the fitness score, we also propose a straightforward yet effective repair approach. For a thorough evaluation, we conduct extensive experiments involving 6 testing methods, 5 datasets, 261 models (including 5 naively trained, 64 repaired, and 192 quantized for on-device deployment), and sixteen combinations of sensitive attributes, showing the superior performance of GRFT and our repair method.

Mobile accessibility is increasingly important nowadays as it enables people with disabilities to use mobile applications to perform daily tasks. Ensuring mobile accessibility not only benefits those with disabilities but also enhances the user experience for all users, making applications more intuitive and user-friendly. Although numerous tools are available for testing and detecting accessibility issues in Android applications, a large number of false negatives and false positives persist due to limitations in the existing approaches, i.e., low coverage of UI scenarios and lack of consideration of runtime context. To address these problems, in this paper, we propose a scenario-driven exploration method for improving the coverage of UI scenarios, thereby detecting accessibility issues within the application, and ultimately reducing false negatives. Furthermore, to reduce false positives caused by not considering the runtime context, we propose a context-aware detection method that provides a more fine-grained detection capability. Our experimental results reveal that A11yScan can detect 1.7X more issues surpassing current state-of-the-art approaches like Xbot ($\mathbf{3, 9 9 1}$vs.$\mathbf{2, 3 2 1}$), thereby reducing the false negative rate by$\mathbf{4 1. 8 4 \%}$. Additionally, it outperforms established UI exploration techniques such as SceneDroid (952 vs. 661 UI scenarios), while achieving comparable activity coverage to recent leading GUI testing tools like GPTDroid on the available dataset (73 % vs. 71%). Meanwhile, with the context-aware detection method, A11yScan effectively reduces the false positive rate by 21 %, validated with a 90.56 % accuracy rate through a user study.

The variety of mobile operating systems available in the market has led to the emergence of cross-platform frameworks, which simplify the development and deployment of mobile applications across multiple platforms simultaneously. Among these, the Flutter framework promoted by Google has become a widely used cross-platform development framework. To date, no work has provided support for the static analysis of Flutter apps on the Android platform. State-of-the-art static analyzers fail to "see" the implicit invocation between the Dart language used by the Flutter framework and the Dalvik bytecode (DEX) used by the native Android platform, posing a significant threat to the completeness of the mobile software analysis.In this paper, we present GlassWing, the first tailored approach to static analysis for Flutter Android apps. GlassWing leverages a data-flow-oriented approach to conduct key program semantic extraction of Flutter apps and discloses the implicit Dart-DEX invocation relations, thereby making cross-language invocation visible. Extensive evaluation on 1,023 popular real-world Flutter apps indicates that GlassWing enhances static analysis of Flutter apps integrated with Soot by parsing 141% more Jimple code lines, extending the call graph with more edges and nodes, and revealing almost 3X potential sensitive data leaks that were previously undetected with FlowDroid. GlassWing sheds light on downstream research fields for Flutter apps (e.g., program graph analysis, taint analysis, and malicious software analysis). Many current and future Android analysis initiatives can be enhanced by seamlessly incorporating GlassWing’s insights.

As web applications grow in popularity, developers are increasingly integrating deep learning (DL) models into these environments. Web-based DL frameworks (e.g., TensorFlow.js) are essential for building and deploying such applications. Therefore, ensuring the quality of these frameworks is critical. While extensive testing efforts have been made for native DL frameworks such as TensorFlow and PyTorch, web-based DL frameworks have not yet undergone systematic testing. A key challenge is generating syntactically and semantically valid inputs while designing effective test oracles for web environments. To address this, we introduce TensorJSFuzz, a novel method for testing web-based DL frameworks. To ensure input quality, TensorJSFuzz extracts constraints directly from the source code of DL operators. By leveraging Large Language Models (e.g., ChatGPT) to understand the code and extract input constraints, TensorJSFuzz performs type-aware random generation coupled with dependency-aware refinement to create high-quality test inputs. These inputs are then subjected to differential testing across various backends, including CPU, TensorFlow, Wasm, and WebGL. Our experimental results show that TensorJSFuzz outperforms all baselines in generating valid inputs and identifying bugs. In particular, TensorJSFuzz successfully detected 92 bugs, with 30 already confirmed or fixed by developers, demonstrating its effectiveness in improving the robustness of web-based DL frameworks.

Malware family labels and key features used for the decision-making of Android malware detection models fall short of precise comprehension of malicious behaviors due to their coarse granularity. To solve these problems, in this paper, we first introduce the concept of the malicious behavior trajectory ( MBT ) and propose an innovative approach called ProMal . ProMal aims to automatically generate malware descriptions with fine granularity through extracted MBTs from malware for users. Specifically, a labeled dataset of MBTs is constructed through substantial human efforts to build a behavioral knowledge graph ( BxKG ). The BxKG is scalable and can be automatically updated using two strategies to ensure its completeness and timeliness: 1) taking into consideration the evolution of Android SDKs, and 2) mining new MBTs by leveraging the widely-used malware datasets. We highlight that the knowledge graph is essential in ProMal , which can reason new MBTs based on existing MBTs because of its structured data representation and semantic relation modeling, and thus helps effectively extract real MBTs in Android malware. We evaluated ProMal on a recent malware dataset where researcher-crafted malware descriptions are available, and the Precision, Recall, and F1-Score of MBT identification based on BxKG reached 96.97%, 91.43%, and 0.94, respectively, outperforming the state-of-the-art approaches. Taking MBTs identified from Android malware as inputs, precise, fine-grained, and human-readable descriptions can be generated using the large language model, whose readability and usability are verified through a user study. The generated descriptions play a significant role in interpreting and comprehending malware behaviors.

Integrating third-party software components is a common practice in modern software development, offering significant advantages in terms of efficiency and innovation. However, this practice is fraught with risks related to software licensing. A lack of understanding may lead to disputes, which can pose serious legal and operational challenges. To these ends, both academia and industry have conducted various investigations and proposed solutions and tools to deal with these challenges. However, significant limitations still remain. Moreover, the rapid evolution of open-source software (OSS) licenses, as well as the rapidly incorporated generative software engineering techniques, such as large language models for code (CodeLLMs), are placing greater demands on the systematic management of software license risks. To unveil the severe challenges and explore possible future directions, we conduct the first systematic literature review (SLR) on 80 carefully selected OSS license-related papers, classifying existing research into three key categories, i.e., license identification, license risk assessment, and license risk mitigation. Based on these, we discuss challenges in existing solutions, conclude the opportunities to shed light on future research directions and offer practical recommendations for practitioners.We hope this thorough review will help bridge the gaps between academia and industry and accelerate the ecosystem-wide governance of legitimate software risks within the software engineering community.

Open-source software (OSS) vulnerabilities are increasingly prevalent, emphasizing the importance of security patches. However, in widely used security platforms like NVD, a substantial number of CVE records still lack trace links to patches. Although rank-based approaches have been proposed for security patch tracing, they heavily rely on handcrafted features in a single-step framework, which limits their effectiveness. In this paper, we propose PatchFinder, a two-phase framework with end-to-end correlation learning for better-tracing security patches. In the initial retrieval phase, we employ a hybrid patch retriever to account for both lexical and semantic matching based on the code changes and the description of a CVE, to narrow down the search space by extracting those commits as candidates that are similar to the CVE descriptions. Afterwards, in the re-ranking phase, we design an end-to-end architecture under the supervised fine-tuning paradigm for learning the semantic correlations between CVE descriptions and commits. In this way, we can automatically rank the candidates based on their correlation scores while maintaining low computation overhead. We evaluated our system against 4,789 CVEs from 532 OSS projects. The results are highly promising: PatchFinder achieves a Recall@10 of 80.63% and a Mean Reciprocal Rank (MRR) of 0.7951. Moreover, the Manual Effort@10 required is curtailed to 2.77, marking a 1.94 times improvement over current leading methods. When applying PatchFinder in practice, we initially identified 533 patch commits and submitted them to the official, 482 of which have been confirmed by CVE Numbering Authorities.

Container Runtime Systems (CRSs), which form the foundational infrastructure of container clouds, are critically important due to their impact on the quality of container cloud implementations. However, a comprehensive understanding of the quality issues present in CRS implementations remains lacking. To bridge this gap, we conduct the first comprehensive empirical study of CRS bugs. Specifically, we gather 429 bugs from 8,271 commits across dominant CRS projects, including runc, gvisor, containerd, and cri-o. Through manual analysis, we develop taxonomies of CRS bug symptoms and root causes, comprising 16 and 13 categories, respectively. Furthermore, we evaluate the capability of popular testing approaches, including unit testing, integration testing, and fuzz testing in detecting these bugs. The results show that 78.79% of the bugs cannot be detected due to the lack of test drivers, oracles, and effective test cases. Based on the findings of our study, we present implications and future research directions for various stakeholders in the domain of CRSs. We hope that our work can lay the groundwork for future research on CRS bug detection.

Current methods for classifying IoT malware predominantly utilize binary and family classifications. However, these outcomes lack the detailed granularity to describe malicious behavior comprehensively. This limitation poses challenges for security analysts, failing to support further analysis and timely preventive actions. To achieve fine-grained malicious behavior identification in the lurking stage of IoT malware, we propose MaGraMal. This approach, leveraging masked graph representation, supplements traditional classification methodology, empowering analysts with critical insights for rapid responses. Through the empirical study, which took three person-months, we identify and summarize four fine-grained malicious behaviors during the lurking stage, constructing an annotated dataset. Our evaluation of 224 algorithm combinations results in an optimized model for IoT malware, achieving an accuracy of 75.83%. The maximum improvement brought by the hybrid features and graph masking achieves 5% and 4.16%, respectively. The runtime overhead analysis showcases MaGraMal’s superiority over the existing dynamic analysis-based detection tool (12x faster). This pioneering work combines machine learning and static features for malicious behavior profiling.

The classification of malicious families is essential in Android malware analysis. However, inconsistent naming standards across different antivirus companies hinder accurate identification and understanding of malicious behaviors. This study conducts an extensive analysis of Android malware families to address these challenges. First, we compared family definitions from various antivirus companies and found significant inconsistencies in the level of detail and descriptions of malicious behaviors. These inconsistencies undermine effective malware classification and analysis. Second, we assessed the alignment between described and exhibited malicious behaviors, revealing that family definitions often provide only a broad outline, omitting critical details. Additionally, evolving malware behaviors often surpass existing family definitions. To address these issues, we propose using specific behavior labels to directly indicate malicious behaviors in malware attack chains. Leveraging large language models (LLMs) and a detailed analysis of Android malicious behaviors, we identified six key behavior labels. To streamline the labeling process, we designed the AMBL frame-work, which automates the generation of behavior labels for malware. Our novel feedback mechanism-based LLM analysis method establishes relationships between APIs and behavior labels, crucial for accurate label updating. Through AMBL, a dataset with behavior analysis reports has been outputed and open sourced. An online survey and manual analysis are also conducted to validate the effectiveness of the AMBL framework and the reliability of the dataset.

Developers usually use third-party libraries (TPLs) to facilitate the development of their projects to avoid reinventing the wheels, however, the vulnerable TPLs indeed cause severe security threats. The majority of existing research only considered whether projects used vulnerable TPLs but neglected whether the vulnerable code of the TPLs was indeed used by the projects, which inevitably results in false positives and further requires additional patching efforts and maintenance costs (e.g., dependency conflict issues after version upgrades). To mitigate such a problem, we proposeVAScanner, which can effectively identify vulnerable root methods causing vulnerabilities in TPLs and further identify all vulnerable APIs of TPLs used by Java projects. Specifically, we first collect the initial patch methods from the patch commits and extract accurate patch methods by employing a patch-unrelated sifting mechanism, then we further identify the vulnerable root methods for each vulnerability by employing an augmentation mechanism. Based on them, we leverage backward call graph analysis to identify all vulnerable APIs for each vulnerable TPL version and construct a database consisting of 90,749 (2,410,779 with library versions) vulnerable APIswith 1.45% false positive proportion with a 95% confidence interval (CI) of [1.31%, 1.59%] from 362 TPLs with 14,775 versions. The database serves as a reference database to help developers detect vulnerable APIs of TPLs used by projects. Our experiments showVAScannereliminates 5.78% false positives and 2.16% false negatives owing to the proposed sifting and augmentation mechanisms. Besides, it outperforms the state-of-the-art method-level vulnerability detection tool in analyzing direct dependencies, Eclipse Steady, achieving more effective detection of vulnerable APIs. Furthermore, to investigate the real impact of vulnerabilities on real open-source projects, we exploitVAScannerto conduct a large-scale analysis on 3,147 projects that depend on vulnerable TPLs, and find only 21.51% of projects (with 1.83% false positive proportion and a 95% CI of [0.71%, 4.61%]) were threatened through vulnerable APIs, demonstrating thatVAScannercan potentially reduce false positives significantly.

To identify security vulnerabilities in Android applications, numerous static application security testing (SAST) tools have been proposed. However, it poses significant challenges to assess their overall performance on diverse vulnerability types. The task is non-trivial and poses considerable challenges. Firstly, the absence of a unified evaluation platform for defining and describing tools’ supported vulnerability types, coupled with the lack of normalization for the intricate and varied reports generated by different tools, significantly adds to the complexity. Secondly, there is a scarcity of adequate benchmarks, particularly those derived from real-world scenarios. To address these problems, we are the first to propose a unified platform namedVulsTotal, supporting various vulnerability types, enabling comprehensive and versatile analysis across diverse SAST tools. Specifically, we begin by meticulously selecting 11 free and open-sourced SAST tools from a pool of 97 existing options, adhering to clearly defined criteria. After that, we invest significant efforts in comprehending the detection rules of each tool, subsequently unifying 67 general/common vulnerability types for Android SAST tools. We also redefine and implement a standardized reporting format, ensuring uniformity in presenting results across all tools. Additionally, to mitigate the problem of benchmarks, we conducted a manual analysis of huge amounts of CVEs to construct a new CVE-based benchmark based on our comprehension of Android app vulnerabilities. Leveraging the evaluation platform, which integrates both existing synthetic benchmarks and newly constructed CVE-based benchmarks from this study, we conducted a comprehensive analysis to evaluate and compare these selected tools from various perspectives, such as general vulnerability type coverage, type consistency, tool effectiveness, and time performance. Our observations yielded impressive findings, like the technical reasons underlying the performance, which provide insights for different stakeholders.

Android API-related compatibility issues have be-come a severe problem and significant challenge for app devel-opers due to the well-known Android fragmentation issues. To address this problem, many effective approaches such as app-based and API lifetime-based methods have been proposed to identify incompatible API usages. However, due to the various implementations of API usages and different API invoking paths, there is still a significant weakness of existing approaches, i.e., introducing a massive number of false positives (FP) and false negatives (FN). To this end, in this paper, we propose PSDroid, an automated compatibility detection approach for Android apps, which aims to reduce FPs and FNs by overcoming several technical bottlenecks. Firstly, we make substantial efforts to carry out a preliminary study to summarize a set of novel API usages with diverse checking implementations. Secondly, we construct a refined API lifetime database by leveraging a semantic resolving analysis on all existing Android SDK frameworks. Based on the above two key phases, we design and implement a novel path-sensitive semantic approach to effectively and automatically detect incompatibility issues. To demonstrate the performance, we compared with five existing approaches (i.e., FicFinder, ACRYL, CIDER, IctAPIFinder, and CID) and the results show that PSDroid outperforms existing tools. We also conducted an in-depth root cause analysis to comprehensively explain the ability of PSDroid in reducing FPs and FNs. Finally, 18/30 reported issues have been confirmed and further fixed by app developers.

With the increasing disclosure of vulnerabilities in open-source software, software composition analysis (SCA) has been widely applied to reveal third-party libraries and the associated vulnerabilities in software projects. Beyond the revelation, SCA tools adopt various remediation strategies to fix vulnerabilities, the quality of which varies substantially. However, ineffective remediation could induce side effects, such as compi-lation failures, which impede acceptance by users. According to our studies, existing SCA tools could not correctly handle the concerns of users regarding the compatibility of remediated projects. To this end, we propose Compatible Remediation of Third-party libraries (CORAL) for Maven projects to fix vulnerabilities without breaking the projects. The evaluation proved that Coralnot only fixed 87.56% of vulnerabilities which outperformed other tools (best 75.32%) and achieved a 98.67% successful compilation rate and a 92.96% successful unit test rate. Furthermore, we found that 78.45% of vulnerabilities in popular Maven projects could be fixed without breaking the compilation, and the rest of the vulnerabilities (21.55%) could either be fixed by upgrades that break the compilations or even be impossible to fix by upgrading.

Quality assurance (QA) tools are receiving more and more attention and are widely used by developers. Given the wide range of solutions for QA technology, it is still a question of evaluating QA tools. Most existing research is limited in the following ways: (i) They compare tools without considering scanning rules analysis. (ii) They disagree on the effectiveness of tools due to the study methodology and benchmark dataset. (iii) They do not separately analyze the role of the warnings. (iv) There is no large-scale study on the analysis of time performance. To address these problems, in the paper, we systematically select 6 free or open-source tools for a comprehensive study from a list of 148 existing Java QA tools. To carry out a comprehensive study and evaluate tools in multi-level dimensions, we first mapped the scanning rules to the CWE and analyze the coverage and granularity of the scanning rules. Then we conducted an experiment on 5 benchmarks, including 1,425 bugs, to investigate the effectiveness of these tools. Furthermore, we took substantial effort to investigate the effectiveness of warnings by comparing the real labeled bugs with the warnings and investigating their role in bug detection. Finally, we assessed these tools’ time performance on 1,049 projects. The useful findings based on our comprehensive study can help developers improve their tools and provide users with suggestions for selecting QA tools.

Due to the competitive environment, mobile apps are usually produced under pressure with lots of complicated functionality and UI pages. Therefore, it is challenging for various roles to design, understand, test, and maintain these apps. The extracted transition graphs for apps such as ATG, WTG, and STG have a low transition coverage and coarse-grained granularity, which limits the existing methods of graphical user interface (GUI) modeling by UI exploration. To solve these problems, in this paper, we propose SceneDroid, a scene-driven exploration approach to extracting the GUI scenes dynamically by integrating a series of novel techniques including smart exploration, state fuzzing, and indirect launching strategies. We present the GUI scenes as a scene transition graph (SceneTG) to model the GUI of apps with high transition coverage and fine-grained granularity. Compared with the existing GUI modeling tools, SceneDroid has improved by 168.74% in the coverage of transition pairs and 162.42% in scene extraction. Apart from the effectiveness evaluation of SceneDroid, we also illustrate the future potential of SceneDroid as a fundamental capability to support app development, reverse engineering, and GUI rearession testing.

Vulnerabilities from third-party libraries (TPLs) have been unveiled to threaten the Maven ecosystem in the long term. Despite patches being released promptly after vulnerabilities are disclosed, the libraries and applications in the community still use the vulnerable versions, which makes the vulnerabilities persistent in the Maven ecosystem (e.g., the notorious Log4Shell still greatly influences the Maven ecosystem nowadays from 2021). Both academic and industrial researchers have proposed user-oriented standards and solutions to address vulnerabilities, while such solutions fail to tackle the ecosystem-wide persistent vulnerabilities because it requires a collective effort from the community to timely adopt patches without introducing breaking issues. To seek an ecosystem-wide solution, we first carried out an empirical study to examine the prevalence of persistent vulnerabilities in the Maven ecosystem. Then, we identified affected libraries for alerts by implementing an algorithm monitoring downstream dependents of vulnerabilities based on an up-to-date dependency graph. Based on them, we further quantitatively revealed that patches blocked by upstream libraries caused the persistence of vulnerabilities. After reviewing the drawbacks of existing countermeasures, to address them, we proposed a solution for range restoration (Ranger) to automatically restore the compatible and secure version ranges of dependencies for downstream dependents. The automatic restoration requires no manual effort from the community, and the code-centric compatibility assurance ensures smooth upgrades to patched versions. Moreover, Ranger along with the ecosystem monitoring can timely alert developers of blocking libraries and suggest flexible version ranges to rapidly unblock patch versions. By evaluation, Ranger could restore 75.64% of ranges which automatically remediated 90.32% of vulnerable downstream projects.

Detecting non-termination is crucial for ensuring program correctness and security, such as preventing denial-of-service attacks. While termination analysis has been studied for many years, existing methods have limited scalability and are only effective on small programs. To address this issue, we propose a practical termination checking technique, called EndWatch, for detecting non-termination caused by infinite loops through testing. Specifically, we introduce two methods to generate non-termination oracles based on checking state revisits, i.e., if the program returns to a previously visited state at the same program location, it does not terminate. The non-termination oracles can be incorporated into testing tools (e.g., AFL used in this paper) to detect non-termination in large programs. For linear loops, we perform symbolic execution on individual loops to infer State Revisit Conditions (SRCs) and instrument SRCs into target loops. For non-linear loops, we instrument target loops for checking concrete state revisits during execution. We evaluated EndWatch on standard benchmarks with small-sized programs and real-world projects with large-sized programs. The evaluation results show that EndWatch is more effective than the state-of-the-art tools on standard benchmarks (detecting 87% of non-terminating programs while the best baseline detects only 67%), and useful in detecting non-termination in real-world projects (detecting 90% of known non-termination CVEs and 4 unknown bugs).

Static application security testing (SAST) takes a significant role in the software development life cycle (SDLC). However, it is challenging to comprehensively evaluate the effectiveness of SAST tools to determine which is the better one for detecting vulnerabilities. In this paper, based on well-defined criteria, we first selected seven free or open-source SAST tools from 161 existing tools for further evaluation. Owing to the synthetic and newly-constructed real-world benchmarks, we evaluated and compared these SAST tools from different and comprehensive perspectives such as effectiveness, consistency, and performance. While SAST tools perform well on synthetic benchmarks, our results indicate that only 12.7% of real-world vulnerabilities can be detected by the selected tools. Even combining the detection capability of all tools, most vulnerabilities (70.9%) remain undetected, especially those beyond resource control and insufficiently neutralized input/output vulnerabilities. The fact is that although they have already built the corresponding detecting rules and integrated them into their capabilities, the detection result still did not meet the expectations. All useful findings unveiled in our comprehensive study indeed help to provide guidance on tool development, improvement, evaluation, and selection for developers, researchers, and potential users.

Approximately 15% of the world's population is suffering from various disabilities or impairments. However, many mobile UX designers and developers disregard the significance of accessibility for those with disabilities when developing apps. It is unbelievable that one in seven people might not have the same level of access that other users have, which actually violates many legal and regulatory standards. On the contrary, if the apps are developed with accessibility in mind, it will drastically improve the user experience for all users as well as maximize revenue. Thus, a large number of studies and some effective tools for detecting accessibility issues have been conducted and proposed to mitigate such a severe problem. However, compared with detection, the repair work is obviously falling behind. Especially for the color-related accessibility issues, which is one of the top issues in apps with a greatly negative impact on vision and user experience. Apps with such issues are difficult to use for people with low vision and the elderly. Unfortunately, such an issue type cannot be directly fixed by existing repair techniques. To this end, we propose Iris, an automated and context-aware repair method to fix the color-related accessibility issues (i.e., the text contrast issues and the image contrast issues) for apps. By leveraging a novel context-aware technique that resolves the optimal colors and a vital phase of attribute-to-repair localization, Iris not only repairs the color contrast issues but also guarantees the consistency of the design style between the original UI page and repaired UI page. Our experiments unveiled that Iris can achieve a 91.38% repair success rate with high effectiveness and efficiency. The usefulness of Iris has also been evaluated by a user study with a high satisfaction rate as well as developers' positive feedback. 9 of 40 submitted pull requests on GitHub repositories have been accepted and merged into the projects by app developers, and another 4 developers are actively discussing with us for further repair. Iris is publicly available to facilitate this new research direction.

Software composition analysis (SCA) tools are proposed to detect potential vulnerabilities introduced by open-source software (OSS) imported as third-party libraries (TPL). With the increasing complexity of software functionality, SCA tools may encounter various scenarios during the dependency resolution process, such as diverse formats of artifacts, diverse dependency imports, and diverse dependency specifications. However, there still lacks a comprehensive evaluation of SCA tools for Java that takes into account the above scenarios. This could lead to a confined interpretation of comparisons, improper use of tools, and hinder further improvements of the tools. To fill this gap, we proposed an Evaluation Model which consists of Scan Modes, Scan Methods, and SCA Scope for Maven (SSM), for comprehensive assessments of the dependency resolving capabilities and effectiveness of SCA tools. Based on the Evaluation Model, we first qualitatively examined 6 SCA tools’ capabilities. Next, the accuracy of dependency and vulnerability is quantitatively evaluated with a large-scale dataset (21,130 Maven modules with 73,499 unique dependencies) under two Scan Modes (i.e., build scan and pre-build scan). The results show that most tools do not fully support SSM, which leads to compromised accuracy. For dependency detection, the average F1-score is 0.890 and 0.692 for build and pre-build respectively, and for vulnerability accuracy, the average F1-score is 0.475. However, proper support for SSM reduces dependency detection false positives by 34.24% and false negatives by 6.91%. This further leads to a reduction of 18.28% in false positives and 8.72% in false negatives in vulnerability reports.

Speaker recognition systems (SRSs) have recently been shown to be vulnerable to adversarial attacks, raising significant security concerns. In this work, we systematically investigate transformation and adversarial training based defenses for securing SRSs. According to the characteristic of SRSs, we present 22 diverse transformations and thoroughly evaluate them using 7 recent promising adversarial attacks (4 white-box and 3 black-box) on speaker recognition. With careful regard for best practices in defense evaluations, we analyze the strength of transformations to withstand adaptive attacks. We also evaluate and understand their effectiveness against adaptive attacks when combined with adversarial training. Our study provides thirteen useful insights and findings, many of them are new or inconsistent with the conclusions in the image and speech recognition domains, e.g., variable and constant bit rate speech compressions have different performance, and some non-differentiable transformations remain effective against current promising evasion techniques which often work well in the image domain. We demonstrate that the proposed novel feature-level transformation combined with adversarial training is rather effective compared to the sole adversarial training in a complete white-box setting, e.g., increasing the accuracy by 13.62% and attack cost by two orders of magnitude, while other transformations do not necessarily improve the overall defense capability. This work sheds further light on the research directions in this field. We also release our evaluation platformSpeakerGuardto foster further research.

Before developing a new mobile app, the development team usually endeavors painstaking efforts to review many existing apps with similar purposes. The review process is crucial in the sense that it reduces market risks and provides inspirations for app development. However, manual exploration of hundreds of existing apps by different roles (e.g., product manager, UI/UX designer, developer, and tester) can be ineffective. For example, it is difficult to completely explore all the functionalities of the app from different aspects including design, implementation, and testing in a short period of time. However, existing reverse engineering tools only provide basic features such as AndroidManifest.xml and Java source files for users. Following the conception of storyboard in movie production, we propose a system, named StoryDistiller, to automatically generate the storyboards for Android apps with rich features through reverse engineering, and assist different roles to review and analyze apps effectively and efficiently. Specifically, we (1) propose a hybrid method to extract a relatively complete Activity transition graph (ATG), that is, it first extracts the ATG of Android apps through static analysis method first, and further leverages dynamic component exploration to augment ATG; (2) extract the required inter-component communication (ICC) data of each target Activity by leveraging static data-flow analysis and renders UI pages dynamically by using app instrumentation together with the extracted required ICC data; (3) obtain rich features including comprehensive ATG with rendered UI pages, semantic activity names, corresponding logic and layout code, etc. (4) implement the storyboard visualization as a web service with the rendered UI pages and the corresponding rich features. Our experiments unveil that StoryDistiller is effective and indeed useful to assist app exploration and review. We also conduct a comprehensive comparison study to demonstrate better performance over IC3, Gator, Stoat, and StoryDroid.

Over the past few years, SMT string solvers have found their applications in an increasing number of domains, such as program analyses in mobile and Web applications, which require the ability to reason about string values. A series of research has been carried out to find quality issues of string solvers in terms of its correctness and performance. Yet, none of them has considered the performance regressions happening across multiple versions of a string solver. To fill this gap, in this paper, we focus on solver performance regressions (SPRs), i.e., unintended slowdowns introduced during the evolution of string solvers. To this end, we developSPRFinderto not only generate test cases demonstrating SPRs, but also localize the probable causes of them, in terms of commits. We evaluated the effectiveness ofSPRFinderon three state-of-the-art string solvers, i.e., Z3Seq, Z3Str3, and CVC4. The results demonstrate thatSPRFinderis effective in generating SPR-inducing test cases and also able to accurately locate the responsible commits. Specifically, the average running time on the target versions is 13.2× slower than that of the reference versions. Besides, we also conducted the first empirical study to peek into the characteristics of SPRs, including the impact of random seed configuration for SPR detection, understanding the root causes of SPRs, and characterizing the regression test cases through case studies. Finally, we highlight that 149 unique SPR-inducing commits were discovered in total bySPRFinder, and 27of them have been confirmed by the corresponding developers.

Deep learning has been widely used for the security issue of vulnerability prediction. However, it is confusing to explain how a deep learning model makes decisions on the prediction, although such a model achieves a good performance. Meanwhile, it is also difficult to discover which part of the source code is concentrated on by this black-box model. To this end, we present an empirical evaluation to explore how the deep learning model works on predicting vulnerability and whether it precisely captures the critical code segments to represent the vulnerable patterns. First of all, we build a new vulnerability dataset, called Juliet+, in which vulnerability-related code lines of both positive (bad) and negative (good) samples are labeled manually with substantial efforts, based on the Juliet Test Suite. After that, four deep learning models by leveraging attention mechanisms are empirically implemented to detect vulnerability through mining vulnerable patterns from the source code. We conduct extensive experiments to evaluate the effectiveness of such four models and to analyze the interpretability with evaluation metrics such as Hit@k. The empirical experiment results reveal that the deep learning models with attention, to some extent, can focus on the vulnerability-related code segments that are profitable to interpret the result of vulnerability detection, especially when we adopt the graph neural network model. We further investigate what factors affect the interpretability of models including the class distribution, the number of samples, and the differences of sample features. We find the graph neural network model performs better on part of the dataset which contains balanced and sufficient samples with obvious differences between vulnerable and non-vulnerable patterns.

Third-party libraries with rich functionalities facilitate the fast development of JavaScript software, leading to the explosive growth of the NPM ecosystem. However, it also brings new security threats that vulnerabilities could be introduced through dependencies from third-party libraries. In particular, the threats could be excessively amplified by transitive dependencies. Existing research only considers direct dependencies or reasoning transitive dependencies based on reachability analysis, which neglects the NPM-specific dependency resolution rules as adapted during real installation, resulting in wrongly resolved dependencies. Consequently, further fine-grained analysis, such as precise vulnerability propagation and their evolution over time in dependencies, cannot be carried out precisely at a large scale, as well as deriving ecosystem-wide solutions for vulnerabilities in dependencies.

To reduce the attack surface from app source code, massive tools focus on detecting security vulnerabilities in Android apps. However, some obvious weaknesses have been highlighted in the previous studies. For example, (1) most of the available tools such as AndroBugs, MobSF, Qark, and Super use pattern-based methods to detect security vulnerabilities. Although they are effective in detecting some types of vulnerabilities, a large number of false positives would be introduced, which inevitably increases the patching overhead for app developers. (2) Similarly, static taint analysis tools such as FlowDroid and IccTA present hundreds of vulnerability candidates of data leakage instead of confirmed vulnerabilities. (3) Last but not least, a relatively complete vulnerability taxonomy is missing, which would introduce a lot of false negatives. In this paper, based on our prior knowledge in this research domain, we empirically propose a vulnerability taxonomy as the baseline and then extend AUSERA by augmenting the detection capability to 50 security vulnerability types. Meanwhile, a new benchmark dataset including all these 50 vulnerability types is constructed to demonstrate the effectiveness of AUSERA. The tool and datasets are available at https://github.com/tjusenchen/AUSERA and the demonstration video can be found at https://youtu.be/UCiGwVaFPpY.

Quality assurance is of great importance for deep learning (DL) systems, especially when they are applied in safety-critical applications. While quality issues of native DL applications have been extensively analyzed, the issues of JavaScript-based DL applications have never been systematically studied. Compared with native DL applications, JavaScript-based DL applications can run on major browsers, making the platform- and device-independent. Specifically, the quality of JavaScript-based DL applications depends on the 3 parts: the application, the third-party DL library used and the underlying DL framework (e.g., TensorFlow.js), called JavaScript-based DL system. In this paper, we conduct the first empirical study on the quality issues of JavaScript-based DL systems. Specifically, we collect and analyze 700 real-world faults from relevant GitHub repositories, including the official TensorFlow.js repository, 13 third-party DL libraries, and 58 JavaScript-based DL applications. To better understand the characteristics of these faults, we manually analyze and construct taxonomies for the fault symptoms, root causes, and fix patterns, respectively. Moreover, we also study the fault distributions of symptoms and root causes, in terms of the different stages of the development lifecycle, the 3-level architecture in the DL system, and the 4 major components of TensorFlow.js framework. Based on the results, we suggest actionable implications and research avenues that can potentially facilitate the development, testing, and debugging of JavaScript-based DL systems.

To enhance the compatibility in the version control of Java Third-party Libraries (TPLs), Maven adopts Semantic Versioning (SemVer) to standardize the underlying meaning of versions, but users could still confront abnormal execution and crash after upgrades even if compilation and linkage succeed. It is caused by semantic breaking (SemB) issues, such that APIs directly used by users have identical signatures but inconsistent semantics across upgrades. To strengthen compliance with SemVer rules, developers and users should be alerted of such issues. Unfortunately, it is challenging to detect them statically, because semantic changes in the internal methods of APIs are difficult to capture. Dynamic testing can confirmingly uncover some, but it is limited by inadequate coverage.

Termination is a crucial program property. Non-termination bugs can be subtle to detect and may remain hidden for long before they take effect. Many real-world programs still suffer from vast consequences (e.g., no response) caused by non-termination bugs. As a classic problem, termination proving has been studied for many years. Many termination checking tools and techniques have been developed and demonstrated effectiveness on existing well-established benchmarks. However, the capability of these tools in finding practical non-termination bugs has yet to be tested on real-world projects. To fill in this gap, in this paper, we conducted the first large-scale empirical study of non-termination bugs in real-world OSS projects. Specifically, we first devoted substantial manual efforts in collecting and analyzing 445 non-termination bugs from 3,142 GitHub commits and provided a systematic classifi-cation of the bugs based on their root causes. We constructed a new benchmark set characterizing the real-world bugs with simplified programs, including a non-termination dataset with 56 real and reproducible non-termination bugs and a termination dataset with 58 fixed programs. With the constructed benchmark, we evaluated five state-of-the-art termination analysis tools. The results show that the capabilities of the tested tools to make correct verdicts have obviously dropped compared with the existing benchmarks. Meanwhile, we identified the challenges and limitations that these tools face by analyzing the root causes of their unhandled bugs. Fi-nally, we summarized the challenges and future research directions for detecting non-termination bugs in real-world projects.

Security vulnerabilities have been continually disclosed and documented. For the effective understanding, management, and mitigation of the fast-growing number of vulnerabilities, an important practice in documenting vulnerabilities is to describe the key vulnerability aspects, such as vulnerability type, root cause, affected product, impact, attacker type, and attack vector. In this article, we first investigate 133,639 vulnerability reports in the Common Vulnerabilities and Exposures (CVE) database over the past 20 years. We find that 56%, 85%, 38%, and 28% of CVEs miss vulnerability type, root cause, attack vector, and attacker type, respectively. By comparing the differences of the latest updated CVE reports across different databases, we observe that 1,476 missing key aspects in 1,320 CVE descriptions were augmented manually in the National Vulnerability Database (NVD) , which indicates that the vulnerability database maintainers try to complete the vulnerability descriptions in practice to mitigate such a problem. To help complete the missing information of key vulnerability aspects and reduce human efforts, we propose a neural-network-based approach called PMA to predict the missing key aspects of a vulnerability based on its known aspects. We systematically explore the design space of the neural network models and empirically identify the most effective model design in the scenario. Our ablation study reveals the prominent correlations among vulnerability aspects when predicting. Trained with historical CVEs, our model achieves 88%, 71%, 61%, and 81% in F1 for predicting the missing vulnerability type, root cause, attacker type, and attack vector of 8,623 “future” CVEs across 3 years, respectively. Furthermore, we validate the predicting performance of key aspect augmentation of CVEs based on the manually augmented CVE data collected from NVD, which confirms the practicality of our approach. We finally highlight that PMA has the ability to reduce human efforts by recommending and augmenting missing key aspects for vulnerability databases, and to facilitate other research works such as severity level prediction of CVEs based on the vulnerability descriptions.

Mobile apps provide new opportunities to people with disabilities to act independently in the world. Following the law of the US, EU, mobile OS vendors such as Google and Apple have included accessibility features in their mobile systems and provide a set of guidelines and toolsets for ensuring mobile app accessibility. Motivated by this trend, researchers have conducted empirical studies by using the inaccessibility issue rate of each page (i.e., screen level) to represent the characteristics of mobile app accessibility. However, there still lacks an empirical investigation directly focusing on the issues themselves (i.e., issue level) to unveil more fine-grained findings, due to the lack of an effective issue detection method and a relatively comprehensive dataset of issues. To fill in this literature gap, we first propose an automated app page exploration tool, named Xbot, to facilitate app accessibility testing and automatically collect accessibility issues by leveraging the instrumentation technique and static program analysis. Owing to the relatively high activity coverage (around 80%) achieved by Xbot when exploring apps, Xbot achieves better performance on accessibility issue collection than existing testing tools such as Google Monkey. With Xbot, we are able to collect a relatively comprehensive accessibility issue dataset and finally collect 86,767 issues from 2,270 unique apps including both closed-source and open-source apps, based on which we further carry out an empirical study from the perspective of accessibility issues themselves to investigate novel characteristics of accessibility issues. Specifically, we extensively investigate these issues by checking 1) the overall severity of issues with multiple criteria, 2) the in-depth relation between issue types and app categories, GUI component types, 3) the frequent issue patterns quantitatively, and 4) the fixing status of accessibility issues. Finally, we highlight some insights to the community and hope to raise the attention to maintaining mobile app accessibility for users especially the elderly and disabled.

Commit messages record code changes (e.g., feature modifications and bug repairs) in natural language, and are useful for program comprehension. Due to the frequent updates of software and time cost, developers are generally unmotivated to write commit messages for code changes. Therefore, automating the message writing process is necessitated. Previous studies on commit message generation have been benefited from generation models or retrieval models, but the code structure of changed code, i.e., AST, which can be important for capturing code semantics, has not been explicitly involved. Moreover, although generation models have the advantages of synthesizing commit messages for new code changes, they are not easy to bridge the semantic gap between code and natural languages which could be mitigated by retrieval models. In this paper, we propose a novel commit message generation model, named ATOM, which explicitly incorporates the abstract syntax tree for representing code changes and integrates both retrieved and generated messages through hybrid ranking. Specifically, the hybrid ranking module can prioritize the most accurate message from both retrieved and generated messages regarding one code change. We evaluate the proposed model ATOM on our dataset crawled from 56 popular Java repositories. Experimental results demonstrate that ATOM increases the state-of-the-art models by 30.72 percent in terms of BLEU-4 (an accuracy measure that is widely used to evaluate text generation systems). Qualitative analysis also demonstrates the effectiveness of ATOM in generating accurate code commit messages.

Mobile apps have become ubiquitous. Ensuring their correctness and reliability is important. However, many apps still suffer from occasional to frequent crashes, weakening their competitive edge. Large-scale, deep analyses of the characteristics of real-world app crashes can provide useful insights to both developers and researchers. However, such studies are difficult and yet to be carried out — this work fills this gap. We collected 16,245 and 8,760 unique exceptions from 2,486 open-source and 3,230 commercial Android apps, respectively, and observed that the exceptions thrown from Android framework (termed“framework-specific exceptions”) account for the majority. With one-year effort, we (1) extensively investigated these framework-specific exceptions, and (2) further conducted an online survey of 135 professional app developers about how they analyze, test, reproduce and fix these exceptions. Specifically, we aim to understand the framework-specific exceptions from several perspectives: (i) their characteristics (e.g., manifestation locations, fault taxonomy), (ii) the developers’ testing practices, (iii) existing bug detection techniques’ effectiveness, (iv) their reproducibility and (v) bug fixes. To enable follow-up research (e.g., bug understanding, detection, localization and repairing), we further systematically constructed,DroidDefects, the first comprehensive and largest benchmark of Android app exception bugs. This benchmark contains 33reproducibleexceptions (with test cases, stack traces, faulty and fixed app versions, bug types, etc.), and 3,696ground-truthexceptions (real faults manifested by automated testing tools), which cover the apps with different complexities and diverse exception types. Based on our findings, we also built two prototype tools: Stoat+, an optimized dynamic testing tool, which quickly uncovered three previously-unknown, fixed crashes in Gmail and Google+; ExLocator, an exception localization tool, which can locate the root causes of specific exception types. Our dataset, benchmark and tools are publicly available onhttps://github.com/tingsu/droiddefects.

Third-party libraries (TPLs) have been widely used in mobile apps, which play an essential part in the entire Android ecosystem. However, TPL is a double-edged sword. On the one hand, it can ease the development of mobile apps. On the other hand, it also brings security risks such as privacy leaks or increased attack surfaces (e.g., by introducing over-privileged permissions) to mobile apps. Although there are already many studies for characterizing third-party libraries, including automated detection, security and privacy analysis of TPLs, TPL attributes analysis, etc., what strikes us odd is that there is no systematic study to summarize those studies’ endeavors. To this end, we conduct the first systematic literature review on Android TPL-related research. Following a well-defined systematic literature review protocol, we collected 74 primary research papers closely related to Android third-party library from 2012 to 2020. After carefully examining these studies, we designed a taxonomy of TPL-related research studies and conducted a systematic study to summarize current solutions, limitations, challenges and possible implications of new research directions related to third-party library analysis. We hope that these contributions can give readers a clear overview of existing TPL-related studies and inspire them to go beyond the current status quo by advancing the discipline with innovative approaches.

As a result of the technical evolution in network technologies and the upper applications, the reliance of mobile apps on the Internet increased heavily on the purpose of excellent service in years. However, the speedy increase brought not only conveniences but also security risks. For instance, it is unveiled that there exists a series of malicious apps, which are aiming to collect users’ private data and imperceptibly send them to remote servers under the camouflage of normal users’ behaviors. To defend against the threat, although lots of research has been proposed, it is still a challenge to capture the abnormal behaviors more precisely. In this paper, we propose IconChecker, a GUI-based anomaly detection framework, to detect icons that can cause malicious network payloads under the premise of users’ normal intentions. IconChecker can detect the abnormal icon-behaviors with the icon's semantics and triggered network traffic in relatively high precision, and further generate a security report for analysis and development. To demonstrate the effectiveness, we evaluate IconChecker from: (1) the accuracy of network traffic sniffing; (2) the accuracy of icon semantics classification; (3) the overall precision of IconChecker towards real apps; (4) comparing IconChecker with the existing tool, i.e., DeepIntent. The detection results show that IconChecker can outperform at the precision of 84% in terms of our summarized 8 categories of icon-behaviors. We remark that IconChecker is the first work, which dynamically detects abnormal icon-behaviors, to identify the malicious network payloads in Android apps.

Common Vulnerabilities and Exposures (CVE) is one of the most influential security databases. With the continuous disclosure of security vulnerabilities, the characteristics of them are documented as vulnerability reports, and it is discovered that their impact on computer systems is increasing. However, as our research continues to deepen, we find that the current lack of key aspects of CVE description is more serious than before. In response to this situation, our research focuses on how to correctly and completely extract key aspect descriptions from various security vulnerability databases to supplement the CVE reports. First, we fetch almost all of semi-structured vulnerability reports from the CVE, Security Focus, and IBM X-Force Exchange databases before November 2020. We then propose a customized NER (Named entity recognition) method based on deep neural networks to extract six key aspects from unstructured descriptions. Finally, we use the corresponding security vulnerability reports in other vulnerability databases to complete the missing key aspects in the correlated CVE description. We conduct sampling surveys on various aspects of this information, and verify the accuracy of extracting key aspects, and find that our method can extract key information from vulnerability descriptions. To demonstrate the usefulness of key aspects augmentation, after completing the missing affected product, root cause, attacker type, attack vector, impact, and vulnerability type in the CVE description, we verify the effectiveness of completing the key aspects of the vulnerability in predicting the severity of the security vulnerability.

Security databases such as Common Vulnerabilities and Exposures (CVE), Common Weakness Enumeration (CWE), and Common Attack Pattern Enumeration and Classification (CAPEC) maintain diverse high-quality security concepts, which are treated as security entities. Meanwhile, security entities are documented with many potential relation types that profit for security analysis and comprehension across these three popular databases. To support reasoning security entity relationships, translation-based knowledge graph representation learning treats each triple independently for the entity prediction. However, it neglects the important semantic information about the neighbor entities around the triples. To address it, we propose a text-enhanced graph attention network model (text-enhanced GAT). This model highlights the importance of the knowledge in the 2−hop neighbors surrounding a triple, under the observation of the diversity of each entity. Thus, we can capture more structural and textual information from the knowledge graph about the security databases. Extensive experiments are designed to evaluate the effectiveness of our proposed model on the prediction of security entity relationships. Moreover, the experimental results outperform the state-of-the-art by Mean Reciprocal Rank (MRR) 0.132 for detecting the missing relationships.

Third-party libraries (TPLs) as essential parts in the mobile ecosystem have become one of the most significant contributors to the huge success of Android, which facilitate the fast development of Android applications. Detecting TPLs in Android apps is also important for downstream tasks, such as malware and repackaged apps identification. To identify in-app TPLs, we need to solve several challenges, such as TPL dependency, code obfuscation, precise version representation. Unfortunately, existing TPL detection tools have been proved that they have not solved these challenges very well, let alone specify the exact TPL versions. To this end, we propose a system, named ATVHunter, which can pinpoint the precise vulnerable in-app TPL versions and provide detailed information about the vulnerabilities and TPLs. We propose a two-phase detection approach to identify specific TPL versions. Specifically, we extract the Control Flow Graphs as the coarse-grained feature to match potential TPLs in the pre-defined TPL database, and then extract opcode in each basic block of CFG as the fine-grained feature to identify the exact TPL versions. We build a comprehensive TPL database (189,545 unique TPLs with 3,006,676 versions) as the reference database. Meanwhile, to identify the vulnerable in-app TPL versions, we also construct a comprehensive and known vulnerable TPL database containing 1,180 CVEs and 224 security bugs. Experimental results show AtVHunter outperforms state-of-the-art TPL detection tools, achieving 90.55% precision and 88.79% recall with high efficiency, and is also resilient to widely-used obfuscation techniques and scalable for large-scale TPL detection. Furthermore, to investigate the ecosystem of the vulnerable TPLs used by apps, we exploit newtool to conduct a large-scale analysis on 104,446 apps and find that 9,050 apps include vulnerable TPL versions with 53,337 vulnerabilities and 7,480 security bugs, most of which are with high risks and are not recognized by app developers.

For the real-world dataset collected by our industrial partner, Pwnzen Infotech Inc., one of the leading industrial security companies, there are a large number of unlabeled Android applications (called unlabeled apps in this paper) that are unlikely to belong to known Android malware families nor ordinary benign apps according to the industrial black-list (i.e., signatures) and white-list (i.e., certificates). However, such apps have rarely been studied previously, but are important to peek into the gray area of mobile world. It is a time-consuming task for software analysts to understand the negative characteristics of these samples, which would lead to potential security or privacy threats for app users, significantly negative impacts on mobile system performance, and bad user experience, etc. To investigate the characteristics of these industrial unlabeled apps in a large-scale in practice, and provide insights to industrial software analysts as well as research communities, we collect a large-scale dataset of unlabeled apps (i.e., 22,886 in total) from our industrial partners. Given the common industrial perception of software analysts that a high percentage of these unlabeled apps could have some similar behaviors, we leverage the popular community-detection techniques based on widely-used app features in mal ware detection to cluster these unlabeled apps. After that, we investigate the common behaviors for different clusters with substantial human efforts and also conduct cross-validation across co-authors to check the results. Our manual analysis unveils the characteristics of these unlabeled apps by sampling data from different clusters, and discovers 11 categories, some of which have never been discovered by previous grayware research. Besides, from our exploration, we find that the community-based techniques are not effective enough in clustering unlabeled apps, so that manual analysis is encouraged. Manual analysis is an important first step towards studying unlabeled apps and understanding their characteristics. Finally, we highlight the lessons learned through real case studies, comparison study with existing malware/grayware research, in-depth discussion with industrial partners, and feedback from industrial partners.

Speaker recognition (SR) is widely used in our daily life as a biometric authentication or identification mechanism. The popularity of SR brings in serious security concerns, as demonstrated by recent adversarial attacks. However, the impacts of such threats in the practical black-box setting are still open, since current attacks consider the white-box setting only.In this paper, we conduct the first comprehensive and systematic study of the adversarial attacks on SR systems (SRSs) to understand their security weakness in the practical black-box setting. For this purpose, we propose an adversarial attack, named FAKEBOB, to craft adversarial samples. Specifically, we formulate the adversarial sample generation as an optimization problem, incorporated with the confidence of adversarial samples and maximal distortion to balance between the strength and imperceptibility of adversarial voices. One key contribution is to propose a novel algorithm to estimate the score threshold, a feature in SRSs, and use it in the optimization problem to solve the optimization problem. We demonstrate that FAKEBOB achieves 99% targeted attack success rate on both open-source and commercial systems. We further demonstrate that FAKEBOB is also effective on both open-source and commercial systems when playing over the air in the physical world. Moreover, we have conducted a human study which reveals that it is hard for human to differentiate the speakers of the original and adversarial voices. Last but not least, we show that four promising defense methods for adversarial attack from the speech recognition domain become ineffective on SRSs against FAKEBOB, which calls for more effective defense methods. We highlight that our study peeks into the security implications of adversarial attacks on SRSs, and realistically fosters to improve the security robustness of SRSs.

Loop invariant plays an important role in program analysis and verification. Equipping each loop with a sound and useful invariant is a crucial step for full program verification and program understanding. However, inferring sound and useful loop invariants remains a challenge due to the complex control structure of loops, especially for loops that contain multiple paths. In this paper, we first analyze the main challenges in loop invariant inference, then introduce a new approach to generate sound and useful loop invariants using a divide-and-conquer strategy. Specifically, we use Path Dependency Automaton (PDA) to model loops by which we boil down the problem of loop invariant inference to state invariant inference of the PDA. We propose an algorithm to infer state invariants of the PDA and construct loop invariants from state invariants. We implement our approach in a tool named InvInfer. We evaluate InvInfer on various benchmarks. The results show that our approach is remarkably more effective and efficient than several state-of-the-art approaches, especially on loops with multiple paths.

Machine learning (ML) based classifiers are vulnerable to evasion attacks, as shown by recent attacks. However, there is a lack of systematic study of evasion attacks on ML-based anti-phishing detection. In this study, we show that evasion attacks are not only effective on practical ML-based classifiers, but can also be efficiently launched without destructing the functionalities and appearance. For this purpose, we propose three mutation-based attacks, differing in the knowledge of the target classifier, addressing a key technical challenge: automatically crafting an adversarial sample from a known phishing website in a way that can mislead classifiers. To launch attacks in the white- and gray-box scenarios, we also propose a sample-based collision attack to gain the knowledge of the target classifier. We demonstrate the efficacy of our evasion attacks on the state-of-the-art, Google's phishing page filter, achieved 100% attack success rate in less than one second per website. Moreover, the transferability attack on BitDefender's industrial phishing page classifier, TrafficLight, achieved up to 81.25% attack success rate. We further propose a similarity-based method to mitigate such evasion attacks, Pelican, which compares the similarity of an unknown website with recently detected phishing websites. We demonstrate that Pelican can effectively detect evasion attacks, hence could be integrated into ML-based classifiers. We also highlight two strategies of classification rule selection to enhance the robustness of classifiers. Our findings contribute to design more robust phishing website classifiers in practice.

Mobile phishing attacks, such as mimic mobile browser pages, masquerade as legitimate applications by leveraging repackaging or clone techniques, have caused varied yet significant security concerns. Consequently, detection techniques have been receiving increasing attention. However, many such detection methods are not well tested and may therefore still be vulnerable to new types of phishing attacks. In this article, we propose a new attacking technique, named GUI-Squatting attack, which can generate phishing apps (phapps) automatically and effectively on the Android platform. Our method adopts image processing and deep learning algorithms, to enable powerful and large-scale attacks. We observe that a successful phishing attack requires two conditions, page confusion and logic deception during attacks synthesis. We directly optimize these two conditions to create a practical attack. Our experimental results reveal that existing phishing defenses are less effective against such emergent attacks and may, therefore, stimulate more efficient detection techniques. To further demonstrate that our generatedphappscan not only bypass existing detection techniques, but also deceive real users, we conduct a human study and successfully steal users’ login information. The human study also shows that different response messages (e.g., “Crash” and “Server failed”) after pressing the login button mislead users to regard our phapps as functionality problems instead of security threats. Extensive experiments reveal that such newly proposed attacks still remain mostly undetected, and are worth further exploration.

Currently, Android malware detection is mostly performed on server side against the increasing number of malware. Powerful computing resource provides more exhaustive protection for app markets than maintaining detection by a single user. However, apart from the applications (apps) provided by the official market (i.e., Google Play Store), apps from unofficial markets and third-party resources are always causing serious security threats to end-users. Meanwhile, it is a time-consuming task if the app is downloaded first and then uploaded to the server side for detection, because the network transmission has a lot of overhead. In addition, the uploading process also suffers from the security threats of attackers. Consequently, a last line of defense on mobile devices is necessary and much-needed. In this paper, we propose an effective Android malware detection system, MobiTive, leveraging customized deep neural networks to provide a real-time and responsive detection environment on mobile devices. MobiTive is a pre-installed solution rather than an app scanning and monitoring engine using after installation, which is more practical and secure. Although a deep learning-based approach can be maintained on server side efficiently for malware detection, original deep learning models cannot be directly deployed and executed on mobile devices due to various performance limitations, such as computation power, memory size, and energy. Therefore, we evaluate and investigate the following key points: (1) the performance of different feature extraction methods based on source code or binary code; (2) the performance of different feature type selections for deep learning on mobile devices; (3) the detection accuracy of different deep neural networks on mobile devices; (4) the real-time detection performance and accuracy on different mobile devices; (5) the potential based on the evolution trend of mobile devices' specifications; and finally we further propose a practical solution (MobiTive) to detect Android malware on mobile devices.

Machine learning–(ML) based approach is considered as one of the most promising techniques for Android malware detection and has achieved high accuracy by leveraging commonly used features. In practice, most of the ML classifications only provide a binary label to mobile users and app security analysts. However, stakeholders are more interested in the reason why apps are classified as malicious in both academia and industry. This belongs to the research area of interpretable ML but in a specific research domain (i.e., mobile malware detection). Although several interpretable ML methods have been exhibited to explain the final classification results in many cutting-edge Artificial Intelligent–based research fields, until now, there is no study interpreting why an app is classified as malware or unveiling the domain-specific challenges. In this article, to fill this gap, we propose a novel and interpretable ML-based approach (named XMal ) to classify malware with high accuracy and explain the classification result meanwhile. (1) The first classification phase of XMal hinges multi-layer perceptron and attention mechanism and also pinpoints the key features most related to the classification result. (2) The second interpreting phase aims at automatically producing neural language descriptions to interpret the core malicious behaviors within apps. We evaluate the behavior description results by leveraging a human study and an in-depth quantitative analysis. Moreover, we further compare XMal with the existing interpretable ML-based methods (i.e., Drebin and LIME) to demonstrate the effectiveness of XMal . We find that XMal is able to reveal the malicious behaviors more accurately. Additionally, our experiments show that XMal can also interpret the reason why some samples are misclassified by ML classifiers. Our study peeks into the interpretable ML through the research of Android malware detection and analysis.

With the proliferation of Android malware, the demand for an effective and efficient malware detection system is on the rise. The existing device-end learning based solutions tend to extract limited syntax features, such as permissions and API calls, to meet a certain time constraint of mobile devices. However, unlike sequence-based features, syntax features lack the semantics which can represent the potential malicious behaviors and further result in more robust model with high accuracy for malware detection. In this paper, we propose an efficient Android malware detection system, named SeqMobile, which adopts behavior-based sequence features and leverages customized deep neural networks on mobile devices instead of the server end. Different from the traditional sequence-based approaches on server end, to meet the performance demand on mobile devices, SeqMobile accepts three effective performance optimization methods to reduce the time of feature extraction and prediction. To evaluate the effectiveness and efficiency of our system, we conduct experiments from the following aspects 1) the detection accuracy of different recurrent neural networks (RNN); 2) the feature extraction performance on different mobile devices, and 3) the detection accuracy and prediction time cost of different sequence lengths. The results unveil that SeqMobile can effectively detect malware with high accuracy. Moreover, our performance optimization methods have proven to improve the performance of training and prediction by at least twofold. Additionally, to discover the potential performance optimization from the state-of-the-art TensorFlow model optimization toolkit for our sequence-based approach, we also provide an evaluation on the toolkit, which can serve as a guidance for other systems leveraging on sequence-based learning approach. Overall, we conclude that our sequence-based approach, together with our performance optimization methods, enable us to efficiently detect malware under the performance demands of mobile devices.

Mobile banking apps, belonging to the most security-critical app category, render massive and dynamic transactions susceptible to security risks. Given huge potential financial loss caused by vulnerabilities, existing research lacks a comprehensive empirical study on the security risks of global banking apps to provide useful insights and improve the security of banking apps.

The purpose of the General Data Protection Regulation (GDPR) is to provide improved privacy protection. If an app controls personal data from users, it needs to be compliant with GDPR. However, GDPR lists general rules rather than exact step-by-step guidelines about how to develop an app that fulfills the requirements. Therefore, there may exist GDPR compliance violations in existing apps, which would pose severe privacy threats to app users. In this paper, we take mobile health applications (mHealth apps) as a peephole to examine the status quo of GDPR compliance in Android apps. We first propose an automated system, named HPDROID, to bridge the semantic gap between the general rules of GDPR and the app implementations by identifying the data practices declared in the app privacy policy and the data relevant behaviors in the app code. Then, based on HPDROID, we detect three kinds of GDPR compliance violations, including the incompleteness of privacy policy, the inconsistency of data collections, and the insecurity of data transmission. We perform an empirical evaluation of 796 mHealth apps. The results reveal that 189 (23.7%) of them do not provide complete privacy policies. Moreover, 59 apps collect sensitive data through different measures, but 46 (77.9%) of them contain at least one inconsistent collection behavior. Even worse, among the 59 apps, only 8 apps try to ensure the transmission security of collected data. However, all of them contain at least one encryption or SSL misuse. Our work exposes severe privacy issues to raise awareness of privacy protection for app users and developers.

Third-party libraries (TPLs) have become a significant part of the Android ecosystem. Developers can employ various TPLs with different functionalities to facilitate their app development. Unfortunately, the popularity of TPLs also brings new challenges and even threats. TPLs may carry malicious or vulnerable code, which can infect popular apps to pose threats to mobile users. Besides, the code of third-party libraries could constitute noises in some downstream tasks (e.g., malware and repackaged app detection). Thus, researchers have developed various tools to identify TPLs. However, no existing work has studied these TPL detection tools in detail; different tools focus on different applications with performance differences, but little is known about them.

Code review is a common process that is used by developers, in which a reviewer provides useful comments or points out defects in the submitted source code changes via pull request. Code review has been widely used for both industry and open-source projects due to its capacity in early defect identification, project maintenance, and code improvement. With rapid updates on project developments, code review becomes a non-trivial and labor-intensive task for reviewers. Thus, an automated code review engine can be beneficial and useful for project development in practice. Although there exist prior studies on automating the code review process by adopting static analysis tools or deep learning techniques, they often require external sources such as partial or full source code for accurate review suggestion. In this paper, we aim at automating the code review process only based on code changes and the corresponding reviews but with better performance. The hinge of accurate code review suggestion is to learn good representations for both code changes and reviews. To achieve this with limited source, we design a multi-level embedding (i.e., word embedding and character embedding) approachto represent the semantics provided by code changes and reviews. The embeddings are then well trained through a proposed attentional deep learning model, as a whole named CORE. We evaluate the effectiveness of CORE on code changes and reviews collected from 19 popular Java projects hosted on Github. Experimental results show that our model CORE can achieve significantly better performance than the state-of-the-art model (DeepMem), with an increase of 131.03% in terms of Recall@10 and 150.69% in terms of Mean Reciprocal Rank. Qualitative general word analysis among project developers also demonstrates the performance of CORE in automating code review.

Currently, Android malware detection is mostly performed on the server side against the increasing number of Android malware. Powerful computing resource gives more exhaustive protection for Android markets than maintaining detection by a single user in many cases. However, apart from the Android apps provided by the official market (i.e., Google Play Store), apps from unofficial markets and third-party resources are always causing a serious security threat to end-users. Meanwhile, it is a time-consuming task if the app is downloaded first and then uploaded to the server side for detection because the network transmission has a lot of overhead. In addition, the uploading process also suffers from the threat of attackers. Consequently, a last line of defense on Android devices is necessary and much-needed. To address these problems, in this paper, we propose an effective Android malware detection system, MobiDroid, leveraging deep learning to provide a real-time secure and fast response environment on Android devices. Although a deep learning-based approach can be maintained on server side efficiently for detecting Android malware, deep learning models cannot be directly deployed and executed on Android devices due to various performance limitations such as computation power, memory size, and energy. Therefore, we evaluate and investigate the different performances with various feature categories, and further provide an effective solution to detect malware on Android devices. The proposed detection system on Android devices in this paper can serve as a starting point for further study of this important area.

Mobile apps are now ubiquitous. Before developing a new app, the development team usually endeavors painstaking efforts to review many existing apps with similar purposes. The review process is crucial in the sense that it reduces market risks and provides inspiration for app development. However, manual exploration of hundreds of existing apps by different roles (e.g., product manager, UI/UX designer, developer) in a development team can be ineffective. For example, it is difficult to completely explore all the functionalities of the app in a short period of time. Inspired by the conception of storyboard in movie production, we propose a system, StoryDroid, to automatically generate the storyboard for Android apps, and assist different roles to review apps efficiently. Specifically, StoryDroid extracts the activity transition graph and leverages static analysis techniques to render UI pages to visualize the storyboard with the rendered pages. The mapping relations between UI pages and the corresponding implementation code (e.g., layout code, activity code, and method hierarchy) are also provided to users. Our comprehensive experiments unveil that StoryDroid is effective and indeed useful to assist app development. The outputs of StoryDroid enable several potential applications, such as the recommendation of UI design and layout code.

Deep Learning (DL) has recently achieved tremendous success. A variety of DL frameworks and platforms play a key role to catalyze such progress. However, the differences in architecture designs and implementations of existing frameworks and platforms bring new challenges for DL software development and deployment. Till now, there is no study on how various mainstream frameworks and platforms influence both DL software development and deployment in practice. To fill this gap, we take the first step towards understanding how the most widely-used DL frameworks and platforms support the DL software development and deployment. We conduct a systematic study on these frameworks and platforms by using two types of DNN architectures and three popular datasets. (1) For development process, we investigate the prediction accuracy under the same runtime training configuration or same model weights/biases. We also study the adversarial robustness of trained models by leveraging the existing adversarial attack techniques. The experimental results show that the computing differences across frameworks could result in an obvious prediction accuracy decline, which should draw the attention of DL developers. (2) For deployment process, we investigate the prediction accuracy and performance (refers to time cost and memory consumption) when the trained models are migrated/quantized from PC to real mobile devices and web browsers. The DL platform study unveils that the migration and quantization still suffer from compatibility and reliability issues. Meanwhile, we find several DL software bugs by using the results as a benchmark. We further validate the results through bug confirmation from stakeholders and industrial positive feedback to highlight the implications of our study. Through our study, we summarize practical guidelines, identify challenges and pinpoint new research directions, such as understanding the characteristics of DL frameworks and platforms, avoiding compatibility and reliability issues, detecting DL software bugs, and reducing time cost and memory consumption towards developing and deploying high quality DL systems effectively.

Mobile apps have become ubiquitous. For app developers, it is a key priority to ensure their apps' correctness and reliability. However, many apps still suffer from occasional to frequent crashes, weakening their competitive edge. Large-scale, deep analyses of the characteristics of real-world app crashes can provide useful insights to guide developers, or help improve testing and analysis tools. However, such studies do not exist --- this paper fills this gap. Over a four-month long effort, we have collected 16,245 unique exception traces from 2,486 open-source Android apps, and observed that framework-specific exceptions account for the majority of these crashes. We then extensively investigated the 8,243 framework-specific exceptions (which took six person-months): (1) identifying their characteristics (e.g., manifestation locations, common fault categories), (2) evaluating their manifestation via state-of-the-art bug detection techniques, and (3) reviewing their fixes. Besides the insights they provide, these findings motivate and enable follow-up research on mobile apps, such as bug detection, fault localization and patch generation. In addition, to demonstrate the utility of our findings, we have optimized Stoat, a dynamic testing tool, and implemented ExLocator, an exception localization tool, for Android apps. Stoat is able to quickly uncover three previously-unknown, confirmed/fixed crashes in Gmail and Google+; ExLocator is capable of precisely locating the root causes of identified exceptions in real-world apps. Our substantial dataset is made publicly available to share with and benefit the community.

Android, the #1 mobile app framework, enforces the single-GUI-thread model, in which a single UI thread manages GUI rendering and event dispatching. Due to this model, it is vital to avoid blocking the UI thread for responsiveness. One common practice is to offload long-running tasks into async threads. To achieve this, Android provides various async programming constructs, and leaves evelopers themselves to obey the rules implied by the model. However, as our study reveals, more than 25% apps violate these rules and introduce hard-to-detect, fail-stop errors, which we term as aysnc programming errors (APEs). To this end, this paper introduces APEChecker, a technique to automatically and efficiently manifest APEs. The key idea is to characterize APEs as specific fault patterns, and synergistically combine static analysis and dynamic UI exploration to detect and verify such errors. Among the 40 real-world Android apps, APEChecker unveils and processes 61 APEs, of which 51 are confirmed (83.6% hit rate). Specifically, APEChecker detects 3X more APEs than the state-of-art testing tools (Monkey, Sapienz and Stoat), and reduces testing time from half an hour to a few minutes. On a specific type of APEs, APEChecker confirms 5X more errors than the data race detection tool, EventRacer, with very few false alarms.

Mobile banking apps, as one of the most contemporary FinTechs, have been widely adopted by banking entities to provide instant financial services. However, our recent work discovered thousands of vulnerabilities in 693 banking apps, which indicates these apps are not as secure as we expected. This motivates us to conduct this study for understanding the current security status of them. First, we take 6 months to track the reporting and patching procedure of these vulnerabilities. Second, we audit 4 state-of the-art vulnerability detection tools on those patched vulnerabilities. Third, we discuss with 7 banking entities via in-person or online meetings and conduct an online survey to gain more feedback from financial app developers. Through this study, we reveal that (1) people may have inconsistent understandings of the vulnerabilities and different criteria for rating severity; (2) state-of-the-art tools are not effective in detecting vulnerabilities that the banking entities most concern; and (3) more efforts should be endeavored in different aspects to secure banking apps. We believe our study can help bridge the existing gaps, and further motivate different parties, including banking entities, researchers and policy makers, to better tackle security issues altogether.

The evolution of mobile malware poses a serious threat to smartphone security. Today, sophisticated attackers can adapt by maximally sabotaging machine-learning classifiers via polluting training data , rendering most recent machine learning-based malware detection tools (such as D rebin , D roid APIM iner , and M a M a D roid ) ineffective. In this paper, we explore the feasibility of constructing crafted malware samples ; examine how machine-learning classifiers can be misled under three different threat models; then conclude that injecting carefully crafted data into training data can significantly reduce detection accuracy. To tackle the problem, we propose K uafu D et , a two-phase learning enhancing approach that learns mobile malware by adversarial detection. K uafu D et includes an offline training phase that selects and extracts features from the training set, and an online detection phase that utilizes the classifier trained by the first phase. To further address the adversarial environment, these two phases are intertwined through a self-adaptive learning scheme, wherein an automated camouflage detector is introduced to filter the suspicious false negatives and feed them back into the training phase. We finally show that K uafu D et can significantly reduce false negatives and boost the detection accuracy by at least 15%. Experiments on more than 250,000 mobile applications demonstrate that K uafu D et is scalable and can be highly effective as a standalone system.

Model-based engineering has emerged as a key set of technologies to engineer software systems. While system source code is expected to match with the designed model, legacy systems and workarounds during deployment would undoubtedly change the source code, making the actual running implementation mismatch with its model. Such mismatch poses a challenge of maintaining the conformance between the model and the corresponding implementation. Prior techniques, such as model checking and model-based testing, simply assumed the sole correctness of the model or the implementation, which is naive since they both could contain correct information (e.g. representing either the software requirements or the actual running environment).In this paper, we aim to address this problem through model-based continuous verification (ConV), an iterative verification process that links the traditional model checking phase with the software testing phase to a feedback loop, ensuring the conformance between the system model and its implementation. It allows to execute the abstract test cases over the implementation through a semi-automatic binding mechanism to guide the update of the code, and augments system properties from the actually running system to guide the update of the model through model checking. Based on these techniques, we implemented Eunomia, a conformance verification system, to support the continuous verification process. Experiments show that Eunomia can effectively detect and locate inconsistencies both in the model and the source code.

Mobile devices are especially vulnerable nowadays to malware attacks, thanks to the current trend of increased app downloads. Despite the significant security and privacy concerns it received, effective malware detection (MD) remains a significant challenge. This paper tackles this challenge by introducing a streaminglized machine learning-based MD framework, StormDroid: (i) The core of StormDroid is based on machine learning, enhanced with a novel combination of contributed features that we observed over a fairly large collection of data set; and (ii) we streaminglize the whole MD process to support large-scale analysis, yielding an efficient and scalable MD technique that observes app behaviors statically and dynamically. Evaluated on roughly 8,000 applications, our combination of contributed features improves MD accuracy by almost 10% compared with state-of-the-art antivirus systems; in parallel our streaminglized process, StormDroid, further improves efficiency rate by approximately three times than a single thread.

This paper proposes Begonia, a malware detection system through Pareto ensemble pruning. We convert the malware detection problem into the bi-objective Pareto optimization, aiming to trade off the classification accuracy and the size of classifiers as two objectives. We automatically generate several groups of base classifiers using SVM and generate solutions through bi-objective Pareto optimization. We then select the ensembles with highest accuracy of each group to form the final solutions, among which we hit the optimal solution where the combined loss function is minimal considering the trade-off between accuracy and time cost. We expect users to provide different trade-off levels to their different requirements to select the best solution. Experimental results show that Begonia can achieve higher accuracy with relatively lower overhead compared to the ensemble containing all the classifiers and can make a good trade-off to different requirements.

Android malware has been found on various third-party online markets, which poses drastic threats to mobile users in terms of security and privacy. Machine learning is one of the promising approaches to discriminate the malicious applications from the benign ones. Despite its higher malware detection capability, a significant challenge remains: in adversarial environment, an attacker can adapt by maximally sabotaging classifiers by polluting training data. This paper proposes KuafuDet, a two-phase learning enhancing approach that adversarially detects the Android malware. Experiments on more than 50,000 Android applications demonstrate the effectiveness and scalability of our approach.