Wenbo Guo 0002

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41ranked-venue papers
9as first author
31since 2021 · last 2025
0000-0002-6890-4503ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 24 · 6 first-author · 18 since 2021Security and privacy · 15 · 3 first-author · 12 since 2021Databases, data management, data science and information retrieval · 3 · 2 first-authorGraphics, computer vision, multimedia, augmented reality and games · 2 · 2 since 2021Software engineering, systems software and programming languages · 1
YearPublicationVenuePosition
2025 F-Fidelity: A Robust Framework for Faithfulness Evaluation of Explainable AI
abstract
Recent research has developed a number of eXplainable AI (XAI) techniques, such as gradient-based approaches, input perturbation-base methods, and black-box explanation methods. While these XAI techniques can extract meaningful insights from deep learning models, how to properly evaluate them remains an open problem. The most widely used approach is to perturb or even remove what the XAI method considers to be the most important features in an input and observe the changes in the output prediction. This approach, although straightforward, suffers the Out-of-Distribution (OOD) problem as the perturbed samples may no longer follow the original data distribution. A recent method RemOve And Retrain (ROAR) solves the OOD issue by retraining the model with perturbed samples guided by explanations. However, using the model retrained based on XAI methods to evaluate these explainers may cause information leakage and thus lead to unfair comparisons. We propose Fine-tuned Fidelity (F-Fidelity), a robust evaluation framework for XAI, which utilizes i) an explanation-agnostic fine-tuning strategy, thus mitigating the information leakage issue, and ii) a random masking operation that ensures that the removal step does not generate an OOD input. We also design controlled experiments with state-of-the-art (SOTA) explainers and their degraded version to verify the correctness of our framework. We conduct experiments on multiple data modalities, such as images, time series, and natural language. The results demonstrate that F-Fidelity significantly improves upon prior evaluation metrics in recovering the ground-truth ranking of the explainers. Furthermore, we show both theoretically and empirically that, given a faithful explainer, F-Fidelity metric can be used to compute the sparsity of influential input components, i.e., to extract the true explanation size.
Xu Zheng 0003, Farhad Shirani Chaharsooghi, Zhuomin Chen, Chaohao Lin, Wei Cheng 0002, Wenbo Guo 0002
ICLR6
2025 PatchPilot: A Cost-Efficient Software Engineering Agent with Early Attempts on Formal Verification
abstract
Recent research builds various patching agents that combine large language models (LLMs) with non-ML tools and achieve promising results on the state-of-the-art (SOTA) software patching benchmark, SWE-bench. Based on how to determine the patching workflows, existing patching agents can be categorized as agent-based planning methods, which rely on LLMs for planning, and rule-based planning methods, which follow a pre-defined workflow. At a high level, agent-based planning methods achieve high patching performance but with a high cost and limited stability. Rule-based planning methods, on the other hand, are more stable and efficient but have key workflow limitations that compromise their patching performance. In this paper, we propose PatchPilot, an agentic patcher that strikes a balance between patching efficacy, stability, and cost-efficiency. PatchPilot proposes a novel rule-based planning workflow with five components: reproduction, localization, generation, validation, and refinement (where refinement is unique to PatchPilot). We introduce novel and customized designs to each component to optimize their effectiveness and efficiency. Through extensive experiments on the SWE-bench benchmarks, PatchPilot shows a superior performance than existing open-source methods while maintaining low cost (less than 1\$ per instance) and ensuring higher stability. We also conduct a detailed ablation study to validate the key designs in each component. Our code is available at https://github.com/ucsb-mlsec/PatchPilot.
Hongwei Li 0025, Yuheng Tang, Shiqi Wang 0032, Wenbo Guo 0002
ICML4
2025 MELON: Provable Defense Against Indirect Prompt Injection Attacks in AI Agents
abstract
Recent research has explored that LLM agents are vulnerable to indirect prompt injection (IPI) attacks, where malicious tasks embedded in tool-retrieved information can redirect the agent to take unauthorized actions. Existing defenses against IPI have significant limitations: either require essential model training resources, lack effectiveness against sophisticated attacks, or harm the normal utilities. We present MELON (Masked re-Execution and TooL comparisON), a novel IPI defense. Our approach builds on the observation that under a successful attack, the agent’s next action becomes less dependent on user tasks and more on malicious tasks. Following this, we design MELON to detect attacks by re-executing the agent’s trajectory with a masked user prompt modified through a masking function. We identify an attack if the actions generated in the original and masked executions are similar. We also include three key designs to reduce the potential false positives and false negatives. Extensive evaluation on the IPI benchmark AgentDojo demonstrates that MELON outperforms SOTA defenses in both attack prevention and utility preservation. Moreover, we show that combining MELON with a SOTA prompt augmentation defense (denoted as MELON-Aug) further improves its performance. We also conduct a detailed ablation study to validate our key designs. Code is available at https://github.com/kaijiezhu11/MELON.
Kaijie Zhu, Xianjun Yang, Jindong Wang 0001, Wenbo Guo 0002, William Yang Wang
ICML4
2025 Demystifying Network Foundation Models
abstract
This work presents a systematic investigation into the latent knowledge encoded within Network Foundation Models (NFMs). Different from existing efforts, we focus on hidden representations analysis rather than pure downstream task performance and analyze NFMs through a three-part evaluation: Embedding Geometry Analysis to assess representation space utilization, Metric Alignment Assessment to measure correspondence with domain-expert features, and Causal Sensitivity Testing to evaluate robustness to protocol perturbations. Using five diverse network datasets spanning controlled and real-world environments, we evaluate four state-of-the-art NFMs, revealing that they all exhibit significant anisotropy, inconsistent feature sensitivity patterns, an inability to separate the high-level context, payload dependency, and other properties. Our work identifies numerous limitations across all models and demonstrates that addressing them can significantly improve model performance (up to 0.35 increase in $F_1$ scores without architectural changes).
Roman Beltiukov, Satyandra Guthula, Wenbo Guo 0002, Walter Willinger, Arpit Gupta
NeurIPS3
2025 Temporal Logic-Based Multi-Vehicle Backdoor Attacks against Offline RL Agents in End-to-end Autonomous Driving
abstract
Assessing the safety of autonomous driving (AD) systems against security threats, particularly backdoor attacks, is a stepping stone for real-world deployment. However, existing works mainly focus on pixel-level triggers which are impractical to deploy in the real world. We address this gap by introducing a novel backdoor attack against the end-to-end AD systems that leverage one or more other vehicles' trajectories as triggers. To generate precise trigger trajectories, we first use temporal logic (TL) specifications to define the behaviors of attacker vehicles. Configurable behavior models are then used to generate these trajectories, which are quantitatively evaluated and iteratively refined based on the TL specifications. We further develop a negative training strategy by incorporating patch trajectories that are similar to triggers but are designated not to activate the backdoor. It enhances the stealthiness of the attack and refines the system’s responses to trigger scenarios. Through extensive experiments on 5 offline reinforcement learning (RL) driving agents with 6 trigger patterns and target actions combinations, we demonstrate the flexibility and effectiveness of our proposed attack, showing the under-exploration of existing end-to-end AD systems' vulnerabilities to such trajectory-based backdoor attacks. Videos of our attack are available at: https://sites.google.com/view/tlbackdoor/home.
Xuan Chen 0003, Shiwei Feng 0002, Zikang Xiong, Shengwei An, Yunshu Mao, Lu Yan, Guanhong Tao 0001, Wenbo Guo 0002, Xiangyu Zhang 0001
NeurIPS8
2025 SECODEPLT: A Unified Benchmark for Evaluating the Security Risks and Capabilities of Code GenAI
abstract
Existing benchmarks for evaluating the security risks and capabilities (e.g., vulnerability detection) of code-generating large language models (LLMs) face several key limitations:(1) limited coverage of risk and capabilities;(2) reliance on static evaluation metrics such as LLM judgments or rule-based detection, which lack the precision of dynamic analysis; and(3) a trade-off between data quality and benchmark scale.To address these challenges, we introduce a general and scalable benchmark construction framework that begins with manually validated, high-quality seed examples and expands them via targeted mutations.Each mutated sample retains the seed’s security semantics while providing diverse, unseen instances. The resulting benchmark bundles every artifact required for dynamic evaluation, including prompts, vulnerable and patched code, test cases, and ground-truth proofs of concept, enabling rigorous measurement of insecure coding, vulnerability detection, and patch generation. Applying this framework to Python, C/C++, and Java, we build SECODEPLT, a dataset of more than 5.9k samples spanning 44 CWE-based risk categories and three security capabilities. Compared with state-of-the-art benchmarks, SECODEPLT offers broader coverage, higher data fidelity, and substantially greater scale. We use SECODEPLT to evaluate leading code-generation LLMs and agents, revealing their strengths and weaknesses in both generating secure code and identifying or fixing vulnerabilities.We provide our code in \url{https://github.com/ucsb-mlsec/SeCodePLT}, data in \url{https://huggingface.co/datasets/UCSB-SURFI/SeCodePLT}
Yuzhou Nie, Zhun Wang, Yu Yang 0007, Ruizhe Jiang, Yuheng Tang, Xander Davies, Yarin Gal, Bo Li 0026, Wenbo Guo 0002, Dawn Song
NeurIPS9
2025 Co-PatcheR: Collaborative Software Patching with Component-specific Small Reasoning Models
abstract
Motivated by the success of general‑purpose large language models (LLMs) in software patching, recent works started to train specialized patching models. Most works trained one model to handle the end‑to‑end patching pipeline (including issue localization, patch generation, and patch validation). However, it is hard for a small model to handle all tasks, as different sub-tasks have different workflows and require different expertise. As such, by using a 70 billion model, SOTA methods can only reach up to 41% resolved rate on SWE-bench-Verified. Motivated by the collaborative nature, we propose Co-PatcheR, the first collaborative patching system with small and specialized reasoning models for individual components. Our key technique novelties are the specific task designs and training recipes. First, we train a model for localization and patch generation. Our localization pinpoints the suspicious lines through a two-step procedure, and our generation combines patch generation and critique. We then propose a hybrid patch validation that includes two models for crafting issue-reproducing test cases with and without assertions and judging patch correctness, followed by a majority vote-based patch selection. Through extensive evaluation, we show that Co-PatcheR achieves 46% resolved rate on SWE-bench-Verified with only 3 x 14B models. This makes Co-PatcheR the best patcher with specialized models, requiring the least training resources and the smallest models. We conduct a comprehensive ablation study to validate our recipes, as well as our choice of training data number, model size, and testing-phase scaling strategy.
Yuheng Tang, Hongwei Li 0025, Kaijie Zhu, Michael Yang, Yangruibo Ding, Wenbo Guo 0002
NeurIPS6
2025 BlockScan: Detecting Anomalies in Blockchain Transactions
abstract
We propose BlockScan, a customized Transformer for anomaly detection in blockchain transactions. Unlike existing methods that rely on rule-based systems or directly apply off-the-shelf large language models (LLMs), BlockScan introduces a series of customized designs to effectively model the unique data structure of blockchain transactions. First, a blockchain transaction is multi-modal, containing blockchain-specific tokens, texts, and numbers. We design a novel modularized tokenizer to handle these multi-modal inputs, balancing the information across different modalities. Second, we design a customized masked language modeling mechanism for pretraining the Transformer architecture, incorporating RoPE embedding and FlashAttention for handling longer sequences. Finally, we design a novel anomaly detection method based on the model outputs. We further provide theoretical analysis for the detection method of our system. Extensive evaluations on Ethereum and Solana transactions demonstrate BlockScan's exceptional capability in anomaly detection while maintaining a low false positive rate. Remarkably, BlockScan is the only method that successfully detects anomalous transactions on Solana with high accuracy, whereas all other approaches achieved very low or zero detection recall scores. This work sets a new benchmark for applying Transformer-based approaches in blockchain data analysis.
Jiahao Yu 0001, Xian Wu 0007, Wenbo Guo 0002, Xinyu Xing 0001
NeurIPS4
2025 Mind the Inconspicuous: Revealing the Hidden Weakness in Aligned LLMs' Refusal Boundaries
Jiahao Yu 0001, Haozheng Luo, Jerry Yao-Chieh Hu, Yan Chen 0004, Wenbo Guo 0002, Han Liu 0001, Xinyu Xing 0001
USENIX Security Symposium5
2024 FORAY: Towards Effective Attack Synthesis against Deep Logical Vulnerabilities in DeFi Protocols
abstract
Blockchain adoption has surged with the rise of Decentralized Finance (DeFi) applications. However, the significant value of digital assets managed by DeFi protocols makes them prime targets for attacks. Current smart contract vulnerability detection tools struggle with DeFi protocols due to deep logical bugs arising from complex financial interactions between multiple smart contracts. These tools primarily analyze individual contracts and resort to brute-force methods for DeFi protocols crossing numerous smart contracts, leading to inefficiency.
Hongbo Wen, Hanzhi Liu, Yanju Chen, Wenbo Guo 0002, Yu Feng 0001
CCS5
2024 SHINE: Shielding Backdoors in Deep Reinforcement Learning
abstract
Recent studies have discovered that a deep reinforcement learning (DRL) policy is vulnerable to backdoor attacks. Existing defenses against backdoor attacks either do not consider RL's unique mechanism or make unrealistic assumptions, resulting in limited defense efficacy, practicability, and generalizability. We propose SHINE, a backdoor shielding method specific for DRL. SHINE designs novel policy explanation techniques to identify the backdoor triggers and a policy retraining algorithm to eliminate the impact of the triggers on backdoored agents. We theoretically justify that SHINE guarantees to improve a backdoored agent's performance in a poisoned environment while ensuring its performance difference in the clean environment before and after shielding is bounded. We further conduct extensive experiments that evaluate SHINE against three mainstream DRL backdoor attacks in various benchmark RL environments. Our results show that SHINE significantly outperforms existing defenses in mitigating these backdoor attacks.
Zhuowen Yuan, Wenbo Guo 0002, Jinyuan Jia 0001, Bo Li 0026, Dawn Song
ICML2
2024 TextGuard: Provable Defense against Backdoor Attacks on Text Classification
Hengzhi Pei, Jinyuan Jia 0001, Wenbo Guo 0002, Bo Li 0026, Dawn Song
NDSS3
2024 Data Free Backdoor Attacks
abstract
Backdoor attacks aim to inject a backdoor into a classifier such that it predicts any input with an attacker-chosen backdoor trigger as an attacker-chosen target class. Existing backdoor attacks require either retraining the classifier with some clean data or modifying the model's architecture. As a result, they are 1) not applicable when clean data is unavailable, 2) less efficient when the model is large, and 3) less stealthy due to architecture changes. In this work, we propose DFBA, a novel retraining-free and data-free backdoor attack without changing the model architecture. Technically, our proposed method modifies a few parameters of a classifier to inject a backdoor. Through theoretical analysis, we verify that our injected backdoor is provably undetectable and unremovable by various state-of-the-art defenses under mild assumptions. Our evaluation on multiple datasets further demonstrates that our injected backdoor: 1) incurs negligible classification loss, 2) achieves 100\% attack success rates, and 3) bypasses six existing state-of-the-art defenses. Moreover, our comparison with a state-of-the-art non-data-free backdoor attack shows our attack is more stealthy and effective against various defenses while achieving less classification accuracy loss. We will release our code upon paper acceptance.
Bochuan Cao, Jinyuan Jia 0001, Chuxuan Hu, Wenbo Guo 0002, Zhen Xiang, Bo Li 0026, Dawn Song
NeurIPS4
2024 When LLM Meets DRL: Advancing Jailbreaking Efficiency via DRL-guided Search
abstract
Recent studies developed jailbreaking attacks, which construct jailbreaking prompts to "fool" LLMs into responding to harmful questions. Early-stage jailbreaking attacks require access to model internals or significant human efforts. More advanced attacks utilize genetic algorithms for automatic and black-box attacks. However, the random nature of genetic algorithms significantly limits the effectiveness of these attacks. In this paper, we propose RLbreaker, a black-box jailbreaking attack driven by deep reinforcement learning (DRL). We model jailbreaking as a search problem and design an RL agent to guide the search, which is more effective and has less randomness than stochastic search, such as genetic algorithms. Specifically, we design a customized DRL system for the jailbreaking problem, including a novel reward function and a customized proximal policy optimization (PPO) algorithm. Through extensive experiments, we demonstrate that RLbreaker is much more effective than existing jailbreaking attacks against six state-of-the-art (SOTA) LLMs. We also show that RLbreaker is robust against three SOTA defenses and its trained agents can transfer across different LLMs. We further validate the key design choices of RLbreaker via a comprehensive ablation study.
Xuan Chen 0003, Yuzhou Nie, Wenbo Guo 0002, Xiangyu Zhang 0001
NeurIPS3
2024 GuideEnricher: Protecting the Anonymity of Ethereum Mixing Service Users with Deep Reinforcement Learning
Ravindu De Silva, Wenbo Guo 0002, Nicola Ruaro, Ilya Grishchenko, Christopher Krügel, Giovanni Vigna
USENIX Security Symposium2
2024 Berkeley Open Extended Reality Recordings 2023 (BOXRR-23): 4.7 Million Motion Capture Recordings from 105,000 XR Users
abstract
Extended reality (XR) devices such as the Meta Quest and Apple Vision Pro have seen a recent surge in attention, with motion tracking "telemetry" data lying at the core of nearly all XR and metaverse experiences. Researchers are just beginning to understand the implications of this data for security, privacy, usability, and more, but currently lack large-scale human motion datasets to study. The BOXRR-23 dataset contains 4,717,215 motion capture recordings, voluntarily submitted by 105,852 XR device users from over 50 countries. BOXRR-23 is over 200 times larger than the largest existing motion capture research dataset and uses a new, highly efficient and purpose-built XR Open Recording (XROR) file format.
Vivek Nair, Wenbo Guo 0002, Rui Wang 0110, James F. O'Brien, Louis B. Rosenberg, Dawn Song
IEEE Trans. Vis. Comput. Graph.2
2023 In Search of netUnicorn: A Data-Collection Platform to Develop Generalizable ML Models for Network Security Problems
abstract
The remarkable success of the use of machine learning-based solutions for network security problems has been impeded by the developed ML models' inability to maintain efficacy when used in different network environments exhibiting different network behaviors. This issue is commonly referred to as the generalizability problem of ML models. The community has recognized the critical role that training datasets play in this context and has developed various techniques to improve dataset curation to overcome this problem. Unfortunately, these methods are generally ill-suited or even counterproductive in the network security domain, where they often result in unrealistic or poor-quality datasets.
Roman Beltiukov, Wenbo Guo 0002, Arpit Gupta, Walter Willinger
CCS2
2023 BIRD: Generalizable Backdoor Detection and Removal for Deep Reinforcement Learning
abstract
Backdoor attacks pose a severe threat to the supply chain management of deep reinforcement learning (DRL) policies. Despite initial defenses proposed in recent studies, these methods have very limited generalizability and scalability. To address this issue, we propose BIRD, a technique to detect and remove backdoors from a pretrained DRL policy in a clean environment without requiring any knowledge about the attack specifications and accessing its training process. By analyzing the unique properties and behaviors of backdoor attacks, we formulate trigger restoration as an optimization problem and design a novel metric to detect backdoored policies. We also design a finetuning method to remove the backdoor, while maintaining the agent's performance in the clean environment. We evaluate BIRD against three backdoor attacks in ten different single-agent or multi-agent environments. Our results verify the effectiveness, efficiency, and generalizability of BIRD, as well as its robustness to different attack variations and adaptions.
Xuan Chen 0003, Wenbo Guo 0002, Guanhong Tao 0001, Xiangyu Zhang 0001, Dawn Song
NeurIPS2
2023 StateMask: Explaining Deep Reinforcement Learning through State Mask
abstract
Despite the promising performance of deep reinforcement learning (DRL) agents in many challenging scenarios, the black-box nature of these agents greatly limits their applications in critical domains. Prior research has proposed several explanation techniques to understand the deep learning-based policies in RL. Most existing methods explain why an agent takes individual actions rather than pinpointing the critical steps to its final reward. To fill this gap, we propose StateMask, a novel method to identify the states most critical to the agent's final reward. The high-level idea of StateMask is to learn a mask net that blinds a target agent and forces it to take random actions at some steps without compromising the agent's performance. Through careful design, we can theoretically ensure that the masked agent performs similarly to the original agent. We evaluate StateMask in various popular RL environments and show its superiority over existing explainers in explanation fidelity. We also show that StateMask has better utilities, such as launching adversarial attacks and patching policy errors.
Zelei Cheng, Xian Wu 0007, Jiahao Yu 0001, Wenhai Sun, Wenbo Guo 0002, Xinyu Xing 0001
NeurIPS5
2023 From Grim Reality to Practical Solution: Malware Classification in Real-World Noise
abstract
Malware datasets inevitably contain incorrect labels due to the shortage of expertise and experience needed for sample labeling. Previous research demonstrated that a training dataset with incorrectly labeled samples would result in inaccurate model learning. To address this problem, researchers have proposed various noise learning methods to offset the impact of incorrectly labeled samples, and in image recognition and text mining applications, these methods demonstrated great success. In this work, we apply both representative and state-of-the-art noise learning methods to real-world malware classification tasks. We surprisingly observe that none of the existing methods could minimize incorrect labels’ impact. Through a carefully designed experiment, we discover that the inefficacy mainly results from extreme data imbalance and the high percentage of incorrectly labeled data samples. As such, we further propose a new noise learning method and name it after MORSE. Unlike existing methods, MORSE customizes and extends a state-of-the-art semi-supervised learning technique. It takes possibly incorrectly labeled data as unlabeled data and thus avoids their potential negative impact on model learning. In MORSE, we also integrate a sample re-weighting method that balances the training data usage in the model learning and thus handles the data imbalance challenge. We evaluate MORSE on both our synthesized and real-world datasets. We show that MORSE could significantly outperform existing noise learning methods and minimize the impact of incorrectly labeled data.
Xian Wu 0007, Wenbo Guo 0002, Baris Coskun, Xinyu Xing 0001
SP2
2023 PATROL: Provable Defense against Adversarial Policy in Two-player Games
Wenbo Guo 0002, Xian Wu 0007, Lun Wang 0001, Xinyu Xing 0001, Dawn Song
USENIX Security Symposium1
2023 Unique Identification of 50, 000+ Virtual Reality Users from Head & Hand Motion Data
Vivek Nair, Wenbo Guo 0002, Justus Mattern, Rui Wang 0110, James F. O'Brien, Louis B. Rosenberg, Dawn Song
USENIX Security Symposium2
2023 AIRS: Explanation for Deep Reinforcement Learning based Security Applications
Jiahao Yu 0001, Wenbo Guo 0002, Gang Wang 0011, Ting Wang 0006, Xinyu Xing 0001
USENIX Security Symposium2
2021 Adversarial Policy Learning in Two-player Competitive Games
abstract
In a two-player deep reinforcement learning task, recent work shows an attacker could learn an adversarial policy that triggers a target agent to perform poorly and even react in an undesired way. However, its efficacy heavily relies upon the zero-sum assumption made in the two-player game. In this work, we propose a new adversarial learning algorithm. It addresses the problem by resetting the optimization goal in the learning process and designing a new surrogate optimization function. Our experiments show that our method significantly improves adversarial agents’ exploitability compared with the state-of-art attack. Besides, we also discover that our method could augment an agent with the ability to abuse the target game’s unfairness. Finally, we show that agents adversarially re-trained against our adversarial agents could obtain stronger adversary-resistance.
Wenbo Guo 0002, Xian Wu 0007, Sui Huang, Xinyu Xing 0001
ICML1
2021 DANCE: Enhancing saliency maps using decoys
abstract
Saliency methods can make deep neural network predictions more interpretable by identifying a set of critical features in an input sample, such as pixels that contribute most strongly to a prediction made by an image classifier. Unfortunately, recent evidence suggests that many saliency methods poorly perform, especially in situations where gradients are saturated, inputs contain adversarial perturbations, or predictions rely upon inter-feature dependence. To address these issues, we propose a framework, DANCE, which improves the robustness of saliency methods by following a two-step procedure. First, we introduce a perturbation mechanism that subtly varies the input sample without changing its intermediate representations. Using this approach, we can gather a corpus of perturbed ("decoy") data samples while ensuring that the perturbed and original input samples follow similar distributions. Second, we compute saliency maps for the decoy samples and propose a new method to aggregate saliency maps. With this design, we offset influence of gradient saturation. From a theoretical perspective, we show that the aggregated saliency map not only captures inter-feature dependence but, more importantly, is robust against previously described adversarial perturbation methods. Our empirical results suggest that, both qualitatively and quantitatively, DANCE outperforms existing methods in a variety of application domains.
Yang Young Lu, Wenbo Guo 0002, Xinyu Xing 0001, William Stafford Noble
ICML2
2021 RNNRepair: Automatic RNN Repair via Model-based Analysis
abstract
Deep neural networks are vulnerable to adversarial attacks. Due to their black-box nature, it is rather challenging to interpret and properly repair these incorrect behaviors. This paper focuses on interpreting and repairing the incorrect behaviors of Recurrent Neural Networks (RNNs). We propose a lightweight model-based approach (RNNRepair) to help understand and repair incorrect behaviors of an RNN. Specifically, we build an influence model to characterize the stateful and statistical behaviors of an RNN over all the training data and to perform the influence analysis for the errors. Compared with the existing techniques on influence function, our method can efficiently estimate the influence of existing or newly added training samples for a given prediction at both sample level and segmentation level. Our empirical evaluation shows that the proposed influence model is able to extract accurate and understandable features. Based on the influence model, our proposed technique could effectively infer the influential instances from not only an entire testing sequence but also a segment within that sequence. Moreover, with the sample-level and segment-level influence relations, RNNRepair could further remediate two types of incorrect predictions at the sample level and segment level.
Xiaofei Xie, Wenbo Guo 0002, Lei Ma 0003, Wei Le, Jian Wang 0067, Lingjun Zhou, Yang Liu 0003, Xinyu Xing 0001
ICML2
2021 BACKDOORL: Backdoor Attack against Competitive Reinforcement Learning
abstract
Recent research has confirmed the feasibility of backdoor attacks in deep reinforcement learning (RL) systems. However, the existing attacks require the ability to arbitrarily modify an agent's observation, constraining the application scope to simple RL systems such as Atari games. In this paper, we migrate backdoor attacks to more complex RL systems involving multiple agents and explore the possibility of triggering the backdoor without directly manipulating the agent's observation. As a proof of concept, we demonstrate that an adversary agent can trigger the backdoor of the victim agent with its own action in two-player competitive RL systems. We prototype and evaluate BackdooRL in four competitive environments. The results show that when the backdoor is activated, the winning rate of the victim drops by 17% to 37% compared to when not activated. The videos are hosted at https://github.com/wanglun1996/multi_agent_rl_backdoor_videos.
Lun Wang 0001, Zaynah Javed, Xian Wu 0007, Wenbo Guo 0002, Xinyu Xing 0001, Dawn Song
IJCAI4
2021 FARE: Enabling Fine-grained Attack Categorization under Low-quality Labeled Data
Wenbo Guo 0002, Tongbo Luo, Vasant G. Honavar, Gang Wang 0011, Xinyu Xing 0001
NDSS2
2021 EDGE: Explaining Deep Reinforcement Learning Policies
abstract
With the rapid development of deep reinforcement learning (DRL) techniques, there is an increasing need to understand and interpret DRL policies. While recent research has developed explanation methods to interpret how an agent determines its moves, they cannot capture the importance of actions/states to a game's final result. In this work, we propose a novel self-explainable model that augments a Gaussian process with a customized kernel function and an interpretable predictor. Together with the proposed model, we also develop a parameter learning procedure that leverages inducing points and variational inference to improve learning efficiency. Using our proposed model, we can predict an agent's final rewards from its game episodes and extract time step importance within episodes as strategy-level explanations for that agent. Through experiments on Atari and MuJoCo games, we verify the explanation fidelity of our method and demonstrate how to employ interpretation to understand agent behavior, discover policy vulnerabilities, remediate policy errors, and even defend against adversarial attacks.
Wenbo Guo 0002, Xian Wu 0007, Usmann Khan, Xinyu Xing 0001
NeurIPS1
2021 Adversarial Policy Training against Deep Reinforcement Learning
Xian Wu 0007, Wenbo Guo 0002, Hua Wei 0001, Xinyu Xing 0001
USENIX Security Symposium2
2021 CADE: Detecting and Explaining Concept Drift Samples for Security Applications
Wenbo Guo 0002, Qingying Hao, Arridhana Ciptadi, Ali Ahmadzadeh, Xinyu Xing 0001, Gang Wang 0011
USENIX Security Symposium2
2020 Towards Inspecting and Eliminating Trojan Backdoors in Deep Neural Networks
abstract
A trojan backdoor is a hidden pattern typically implanted in a deep neural network (DNN). It could be activated and thus forces that infected model to behave abnormally when an input sample with a particular trigger is fed to that model. As such, given a DNN and clean input samples, it is challenging to inspect and determine the existence of a trojan backdoor. Recently, researchers design and develop several pioneering solutions to address this problem. They demonstrate that the proposed techniques have great potential in trojan detection. However, we show that none of these existing techniques completely address the problem. On the one hand, they mostly work under an unrealistic assumption of assuming the availability of the contaminated training database. On the other hand, these techniques can neither accurately detect the existence of trojan backdoors, nor restore high-fidelity triggers, especially when infected models are trained with high-dimensional data, and the triggers pertaining to the trojan vary in size, shape, and position. In this work, we propose TABOR, a new trojan detection technique. Conceptually, it formalizes the detection of a trojan backdoor as solving an optimization objective function. Different from the existing technique which also models trojan detection as an optimization problem, TABOR first designs a new objective function that could guide optimization to identify a trojan backdoor more correctly and accurately. Second, TABOR borrows the idea of interpretable AI to further prune the restored triggers. Last, TABOR designs a new anomaly detection method, which could not only facilitate the identification of intentionally injected triggers but also filter out false alarms (i.e., triggers detected from an uninfected model). We train 112 DNNs on five datasets and infect these models with two existing trojan attacks. We evaluate TABOR by using these infected models, and demonstrate that TABOR has much better performance in trigger restoration, trojan detection, and elimination than Neural Cleanse, the state-of-the-art trojan detection technique.
Wenbo Guo 0002, Lun Wang 0001, Yan Xu 0019, Xinyu Xing 0001, Min Du 0003, Dawn Song
ICDM1
2019 RENN: Efficient Reverse Execution with Neural-Network-Assisted Alias Analysis
abstract
Reverse execution and coredump analysis have long been used to diagnose the root cause of software crashes. Each of these techniques, however, face inherent challenges, such as insufficient capability when handling memory aliases. Recent works have used hypothesis testing to address this drawback, albeit with high computational complexity, making them impractical for real world applications. To address this issue, we propose a new deep neural architecture, which could significantly improve memory alias resolution. At the high level, our approach employs a recurrent neural network (RNN) to learn the binary code pattern pertaining to memory accesses. It then infers the memory region accessed by memory references. Since memory references to different regions naturally indicate a non-alias relationship, our neural architecture can greatly reduce the burden of doing hypothesis testing to track down non-alias relation in binary code. Different from previous researches that have utilized deep learning for other binary analysis tasks, the neural network proposed in this work is fundamentally novel. Instead of simply using off-the-shelf neural networks, we designed a new recurrent neural architecture that could capture the data dependency between machine code segments. To demonstrate the utility of our deep neural architecture, we implement it as RENN, a neural network-assisted reverse execution system. We utilize this tool to analyze software crashes corresponding to 40 memory corruption vulnerabilities from the real world. Our experiments show that RENN can significantly improve the efficiency of locating the root cause for the crashes. Compared to a state-of-the-art technique, RENN has 36.25% faster execution time on average, detects an average of 21.35% more non-alias pairs, and successfully identified the root cause of 12.5% more cases.
Dongliang Mu, Wenbo Guo 0002, Alejandro Cuevas, Yueqi Chen 0001, Jinxuan Gai, Xinyu Xing 0001, Bing Mao 0001, Chengyu Song
ASE2
2019 Building Adversarial Defense with Non-invertible Data Transformations
Wenbo Guo 0002, Dongliang Mu, Ligeng Chen, Jinxuan Gai
PRICAI (3)1
2019 Towards the Detection of Inconsistencies in Public Security Vulnerability Reports
Wenbo Guo 0002, Yueqi Chen 0001, Xinyu Xing 0001, Gang Wang 0011
USENIX Security Symposium2
2019 DEEPVSA: Facilitating Value-set Analysis with Deep Learning for Postmortem Program Analysis
Wenbo Guo 0002, Dongliang Mu, Xinyu Xing 0001, Min Du 0003, Dawn Song
USENIX Security Symposium1
2018 LEMNA: Explaining Deep Learning based Security Applications
abstract
While deep learning has shown a great potential in various domains, the lack of transparency has limited its application in security or safety-critical areas. Existing research has attempted to develop explanation techniques to provide interpretable explanations for each classification decision. Unfortunately, current methods are optimized for non-security tasks ( e.g., image analysis). Their key assumptions are often violated in security applications, leading to a poor explanation fidelity. In this paper, we propose LEMNA, a high-fidelity explanation method dedicated for security applications. Given an input data sample, LEMNA generates a small set of interpretable features to explain how the input sample is classified. The core idea is to approximate a local area of the complex deep learning decision boundary using a simple interpretable model. The local interpretable model is specially designed to (1) handle feature dependency to better work with security applications ( e.g., binary code analysis); and (2) handle nonlinear local boundaries to boost explanation fidelity. We evaluate our system using two popular deep learning applications in security (a malware classifier, and a function start detector for binary reverse-engineering). Extensive evaluations show that LEMNA's explanation has a much higher fidelity level compared to existing methods. In addition, we demonstrate practical use cases of LEMNA to help machine learning developers to validate model behavior, troubleshoot classification errors, and automatically patch the errors of the target models.
Wenbo Guo 0002, Dongliang Mu, Jun Xu 0024, Purui Su, Gang Wang 0011, Xinyu Xing 0001
CCS1
2018 Defending Against Adversarial Samples Without Security through Obscurity
abstract
It has been recently shown that deep neural networks (DNNs) are susceptible to a particular type of attack that exploits a fundamental flaw in their design. This attack consists of generating particular synthetic examples referred to as adversarial samples. These samples are constructed by slightly manipulating real data-points that change "fool" the original DNN model, forcing it to misclassify previously correctly classified samples with high confidence. Many believe addressing this flaw is essential for DNNs to be used in critical applications such as cyber security. Previous work has shown that learning algorithms that enhance the robustness of DNN models all use the tactic of "security through obscurity". This means that security can be guaranteed only if one can obscure the learning algorithms from adversaries. Once the learning technique is disclosed, DNNs protected by these defense mechanisms are still susceptible to adversarial samples. In this work, we investigate by examining how previous research dealt with this and propose a generic approach to enhance a DNN's resistance to adversarial samples. More specifically, our approach integrates a data transformation module with a DNN, making it robust even if we reveal the underlying learning algorithm. To demonstrate the generality of our proposed approach and its potential for handling cyber security applications, we evaluate our method and several other existing solutions on datasets publicly available, such as a large scale malware dataset and MNIST and IMDB datasets. Our results indicate that our approach typically provides superior classification performance and robustness to attacks compared with state-of-art solutions.
Wenbo Guo 0002, Qinglong Wang 0003, Kaixuan Zhang 0002, Alexander Ororbia, Sui Huang, Xue (Steve) Liu, C. Lee Giles, Lin Lin 0003, Xinyu Xing 0001
ICDM1
2018 Explaining Deep Learning Models - A Bayesian Non-parametric Approach
abstract
Understanding and interpreting how machine learning (ML) models make decisions have been a big challenge. While recent research has proposed various technical approaches to provide some clues as to how an ML model makes individual predictions, they cannot provide users with an ability to inspect a model as a complete entity. In this work, we propose a novel technical approach that augments a Bayesian non-parametric regression mixture model with multiple elastic nets. Using the enhanced mixture model, we can extract generalizable insights for a target model through a global approximation. To demonstrate the utility of our approach, we evaluate it on different ML models in the context of image recognition. The empirical results indicate that our proposed approach not only outperforms the state-of-the-art techniques in explaining individual decisions but also provides users with an ability to discover the vulnerabilities of the target ML models.
Wenbo Guo 0002, Sui Huang, Yunzhe Tao, Xinyu Xing 0001, Lin Lin 0003
NeurIPS1
2018 Active learning support vector machines with low-rank transformation
abstract
Active learning has proven to be quite effective in a vast array of machine learning tasks. Despite the lower labeling cost of active learning, it has been shown that active learning still can not reach state-of-the-art performance on several classification tasks and is sensitive to initial state. In this work, we propose a novel algorithm to improve the performance of active learning and it’s robustness to initial state. More specifically, we integrate low-rank transformation (LRT) with active learning. In each iteration, LRT is applied to project original high dimensional data to a feature space where data are easier to be classified and then support vector machines classifier is updated in this feature space. As iteration goes on, active learning’s propriety of labeling data improves the performance of LRT, which further promotes the accuracy of SVM classifier. Experiment on several benchmark binary classification datasets results showed the proposed algorithm outperforms other active learning methods in accuracy and robustness.
Wenbo Guo 0002, Yupu Yang
Intell. Data Anal.2
2017 Adversary Resistant Deep Neural Networks with an Application to Malware Detection
abstract
Outside the highly publicized victories in the game of Go, there have been numerous successful applications of deep learning in the fields of information retrieval, computer vision, and speech recognition. In cybersecurity, an increasing number of companies have begun exploring the use of deep learning (DL) in a variety of security tasks with malware detection among the more popular. These companies claim that deep neural networks (DNNs) could help turn the tide in the war against malware infection. However, DNNs are vulnerable to adversarial samples, a shortcoming that plagues most, if not all, statistical and machine learning models. Recent research has demonstrated that those with malicious intent can easily circumvent deep learning-powered malware detection by exploiting this weakness.
Qinglong Wang 0003, Wenbo Guo 0002, Kaixuan Zhang 0002, Alexander Ororbia, Xinyu Xing 0001, Xue (Steve) Liu, C. Lee Giles
KDD2