Finding similar code is important for software engineering, defense of intellectual property, and security, and one of the increasingly common ways adversaries use to defeat the detection of similar code is through obfuscations such as code transformation and scattering the code they wish to hide among long sequences. Moving code far enough apart poses a specific challenge for solutions with localized features (e.g., n-grams), or attention mechanisms as the code parts are distributed beyond the local context window. We introduce a neural network solution pattern called “Cybertron” that addresses this problem by utilizing reinforcement learning to train a code abstraction and summarization function; this converts arbitrarily long code into fixed-length real vectors in a way that is optimized for similarity search. The key to the design is the smart selection of important elements of the code and abstraction to preserve semantic function while minimizing syntactic feature information. We evaluated the approach on a three-challenge benchmark of obfuscated JavaScript, a scripting language that is commonly obfuscated and for which code-mixing is a rising challenge. The evaluation shows our approach identifies obfuscated code within even large scripts with an AUC of 78%, which outperforms current state-of-the-art sequence models by 7–35%.

Software vulnerabilities are a challenge in cybersecurity. Manual security patches are often difficult and slow to be deployed, while new vulnerabilities are created. Binary code vulnerability detection is less studied and more complex compared to source code, and this has important practical implications. Deep learning has become an efficient and powerful tool in the security domain, where it provides end-to-end and accurate prediction. Modern deep learning approaches learn the program semantics through sequence and graph neural networks, using various intermediate representation of programs, such as abstract syntax trees (AST) or control flow graphs (CFG). Due to the complex nature of program execution, the output of an execution depends on the many program states and inputs. Also, a CFG generated from static analysis can be an overestimation of the true program flow. Moreover, the size of programs often does not allow a graph neural network with fixed layers to aggregate global information. To address these issues, we propose DeepEXE, an agent-based implicit neural network that mimics the execution path of a program. We use reinforcement learning to enhance the branching decision at every program state transition and create a dynamic environment to learn the dependency between a vulnerability and certain program states. An implicitly defined neural network enables nearly infinite state transitions until convergence, which captures the structural information at a higher level. The experiments are conducted on two semi-synthetic and two real-world datasets. We show that DeepEXE is an accurate and efficient method and outperforms the state-of-the-art vulnerability detection methods.

Malware attacks are posing a significant threat to national security, cooperate network, and public endpoint security. Identifying the Advanced Persistent Threat (APT) groups behind the attacks and grouping their activities into attack campaigns help security investigators trace their activities thus providing better security protections against future attacks. Existing Cyber Threat Intelligent (CTI) components mainly focus on malware family identification and behavior characterization, which cannot solve the APT tracking problem: while APT tracking needs one to link malware binaries of multiple families to a single threat actor, these behavior or function-based techniques are tightened up to a specific attack technique and would fail on connecting different families. Binary Authorship Attribution (AA) solutions could discriminate against threat actors based on their stylometric traits. However, AA solutions assume that the author of a binary is within a fixed candidate author set. However, real-world malware binaries may be created by a new unknown threat actor. To address this research gap, we propose VeriBin for the Binary Authorship Verification (BAV) problem. VeriBin is a novel adversarial neural network that extracts functionality-agnostic style representations from assembly code for the AV task. The extracted style representations can be visualized and are explainable with VeriBin’s multi-head attention mechanism. We benchmark VeriBin with state-of-the-art coding style representations on a standard dataset and a recent malware-APT dataset. Given two anonymous binaries of out-of-sample authors, VeriBin can accurately determine whether they belong to the same author or not. VeriBin is resilient to compiler optimizations and robust against malware family variants.

Binary code similarity detection serves a critical role in cybersecurity. It alleviates the huge manual effort required in the reverse engineering process for malware analysis and vulnerability detection, where the original source code is often not available. Most of the existing solutions focus on a manual feature engineering process and customized code matching algorithms that are inefficient and inaccurate. Recent deep learning-based solutions embed the semantics of binary code into a latent space through supervised contrastive learning. However, one cannot cover all the possible forms in the training set to learn the variance of the same semantics. In this paper, we propose an unsupervised model aiming to learn the intrinsic representation of assembly code semantics. Specifically, we propose a Transformer-based auto-encoder like language model for the low-level assembly code grammar to capture the abstract semantic representation. By coupling a Transformer encoder and a skip-gram style loss design, it can learn a compact representation that is robust against different compilation options. We conduct experiments on four different block-level code similarity tasks. It shows that our method is more robust compared to the state-of-the-art solutions.