Recently, APT attacks have frequently happened, which are increasingly complicated. Research on dynamic detection and tracing of APT via audit logs has been widely of concern. For Windows, ETW(events tracing for Windows) is a well-known built-in kernel-level logs collection framework. However, existing log collection tools built on ETW suffer from working shortages, including data loss, high overhead, and weak real-time performance. Therefore, It is still challenging to directly apply ETW-based Windows tools to analyze APT attack scenarios. To address these challenges, this paper proposes an efficient and lossless kernel log collector based on ETW called Kellect. The collector dynamically optimizes the number of cache and processing threads through a multi-level cache for lossless collecting and significantly enhances analysis performance by replacing the native TDH library with a sliding pointer. Furthermore, Kellect enhances log semantics understanding by maintaining event mappings and application callstacks which provide more comprehensive characteristics for security event behavior analysis. Additionally, Kellect has compatibility with different OS versions.With plenty of experiments, Kellect demonstrates its capability to achieve non-destructive, real-time, and full collection of kernel log data generated from events with a comprehensive efficiency of 9 times greater than existing tools. It only takes extra CPU usage with approximately 2%–3% and about 40MB memory consumption. As a killer illustration to show how Kellect can work for APT, full data logs have been collected as a dataset Kellect4APT, generated by implementing diversity TTPs from the latest ATT&CK. To our best knowledge, it is the first open benchmark dataset representing ATT&CK technique-specific behaviors, which could be highly expected to improve more extensive research on APT studies.
APT (Advanced Persistent Threat) with the characteristics of persistence, stealth, and diversity is one of the greatest threats against cyber-infrastructure. As a countermeasure, existing studies leverage provenance graphs to capture the complex relations between system entities in a host for effective APT detection. In addition to detecting single attack events as most existing work does, understanding the tactics / techniques (e.g., Kill-Chain, ATT&CK) applied to organize and accomplish the APT attack campaign is also important for security operations. Existing studies try to manually design a set of rules to map low-level system events to high-level APT tactics / techniques. However, the rule based methods are coarse-grained and lack generalization ability. Thus, they can only recognize APT tactics and have difficulty in identifying APT techniques. They also cannot adapt to mutant behaviors of existing APT tactics / techniques. In this paper, we propose TREC, the first attempt to recognize APT tactics / techniques from provenance graphs by exploiting deep learning techniques. To address the "needle in a haystack" problem, TREC segments small and compact subgraphs covering individual APT technique instances from a large provenance graph based on a malicious node detection model and a subgraph sampling algorithm. To address the "training sample scarcity" problem, TREC trains the APT tactic / technique recognition model in a few-shot learning manner by adopting a Siamese neural network. We evaluate TREC based on a customized dataset collected and made public by our team. The experiment results show that TREC significantly outperforms state-of-the-art systems in APT tactic recognition and TREC can also effectively identify APT techniques.
Anomaly detection is essential to ensuring system security and reliability. As one of the basic techniques in the cyberattack, the existing malicious traffic classification method has been facing diverse challenges such as insufficient samples, poor denoising ability, and weak generalization of the classification model. In this paper, we propose a novel method for detecting malicious HTTP traffic based on a framework (HTTPSmell; it refers to the sniffing of some network attacks launched by exploiting the HTTP protocol.)), and XSS dataset obtained from GitHub that automatically applies a deep learning model with high generalization ability even under a small training dataset. With HTTPSmell, we are able to achieve positive results from a semisupervised model that leverages the unsupervised data augmentation (UDA) and the keywords library avoidance (KLA)-based data augmentation method that holds higher learning generalization, higher scenario coverage rate, and better detection efficiency in the smaller training samples. Finally, we demonstrate through comprehensive experiments in the realistic enterprise environment that HTTPSmell can achieve an accuracy of 96.77% for identifying complex and advanced cyberattacks, while only maintaining a constant 60 MB of memory and sustaining up to 27 k/s throughput.