A webshell is a malicious backdoor that allows remote access and control to a web server by executing arbitrary commands. The wide use of obfuscation and encryption technologies has greatly increased the difficulty of webshell detection. To this end, we propose a novel webshell detection model leveraging the grammatical features extracted from the PHP code. The key idea is to combine the executable data characteristics of the PHP code with static text features for webshell classification. To verify the proposed model, we construct a cleaned data set of webshell consisting of 2,917 samples from 17 webshell collection projects and conduct extensive experiments. We have designed three sets of controlled experiments, the results of which show that the accuracy of the three algorithms has reached more than 99.40%, the highest reached 99.66%, the recall rate has been increased by at least 1.8%, the most increased by 6.75%, and the F1 value has increased by 2.02% on average. It not only confirms the efficiency of the grammatical features in webshell detection but also shows that our system significantly outperforms several state‐of‐the‐art rivals in terms of detection accuracy and recall rate.
1 January 2023 in International Journal of Intelligent Systems
As the complexity of cyberattacks continues to increase, multistage combination attacks have become the primary method of attack. Attackers plan and organize a series of attack steps, using various attack tools to achieve specific goals. Extracting knowledge about these tools is of great significance for both defense and tracing of attacks. We have noticed that there is a wealth of security tool‐related knowledge within the open‐source community, but research in this area is limited. It is challenging to achieve large‐scale automated security tool information extraction. To address this, we propose automated knowledge graph construction architecture, named SecTKG, for open‐source security tools. Our approach involves designing a security tool ontology model to describe tools, users, and relationships, which guides the extraction of security tool knowledge. In addition, we develop advanced entity recognition and classification methods, ensuring efficient and accurate knowledge extraction. As far as we know, this work is the first to construct the large‐scale security tool knowledge graph, containing 4 million entities and 10 million relationships. Furthermore, we investigate the tendencies and particularities of security tools based on the SecTKG and developed a security tool influence‐measuring application. The research fills a gap in the field of automated security tools’ knowledge extraction and provides a foundation for future research and practical applications.
9 April 2024 in IEEE Transactions on Industrial Informatics
Penetration testing is widely acknowledged as the foremost method for evaluating network security. However, three challenges impede the generation of strategies that align with human expectations. In this article, we present, for the first time, a method based on human feedback to enhance strategy generation. Our approach comprises two components: agent training and decision-making. During agent training, we establish a hierarchical framework to decompose tasks and a knowledge base to offer advice for improving data efficiency. We then impose constraints on the action space to mitigate ineffective exploration. Finally, we train a reward model based on human feedback and fine tune the model guided by this reward model. In decision-making, we process the model output to enhance decision accuracy. We crafted scenarios based on real-world networks, and the results demonstrate the effectiveness of our method in generating penetration testing strategies that align more closely with human intentions.
Affected by various error factors in the actual environment, the accuracy of the direction of arrival (DOA) estimation algorithm will greatly decrease during an application. To address this issue, in this paper, we propose an intelligent DOA estimation error calibration method based on transfer learning, which learns error knowledge from a small number of actual signal samples and improves the DOA estimation accuracy in the real application. We constructed a deep convolutional neural network (CNN)-based intelligent DOA estimation model to learn the mapping between the input signals and their azimuths. We generated a large number of ideal simulation signal samples to train the CNN model and used it as the pretrained model. Then, we fine-tuned the CNN model with a small number of actual signal samples collected in the actual environment. We demonstrate the effectiveness of the proposed method through simulation experiments. The experimental results indicate that the proposed method can effectively improve the accuracy of DOA estimation in the actual environment.
Web applications widely use the logging functionality, but improper handling can bring serious security threats. An attacker can trigger the execution of malicious data by writing malicious data to the web application logs and then accessing the view–logs interface, resulting in a vulnerability of the web application log injection. However, detecting this type of vulnerability requires automatic discovery of log-injectable interfaces and view–logs interfaces, which is difficult. In addition, bypasssing the application-specific input-filtering checks to write an effective payload to the log is also challenging. This paper proposes LogInjector, an efficient web application log injection vulnerability detection method. First, it obtains the log storage form and location and then finds the log-injectable interfaces through the extended dynamic crawler. Second, it automatically identifies the web application view–logs interfaces. Finally, LogInjector utilizes a dynamic testing approach based on the feedback-guided mutation to detect web application log injection vulnerabilities. To verify the effectiveness of LogInjector, we test it in 14 popular web applications in real-world cases and compare it with Black Widow, the state-of-the-art web vulnerability scanner. LogInjector detects 16 web application log injection vulnerabilities, including 6 zero-day vulnerabilities, while Black Widow can only detect three log injection vulnerabilities, demonstrating the effectiveness of LogInjector in practice.
Identifying network protocol vulnerabilities is critical for cyberspace security. Generation-based black-box protocol fuzzing is widely used but faces challenges: over-reliance on manual protocol analysis and script writing, single-threaded fuzzing, and lack of dynamic fuzzing strategy optimization. To address these, we propose LLM-Boofuzz, a generation-based black-box protocol fuzzing framework via Large Language Models (LLMs). It leverages LLMs to parse real traffic to extract protocol information, guides LLMs to generate executable scripts with a repair mechanism, and enables multi-script iterative fuzzing via an LLM-based agent. Experiments show that LLM-Boofuzz outperforms state-of-the-art tools: it triggers all 15 test vulnerabilities (vs. 8/7/7 for Boofuzz/Snipuzz/AFLNet) and achieves an average 53.4% code line coverage on two protocol programs (vs. 30.65%/31.95%/41.65%), providing an efficient solution for network protocol fuzzing.