Boubakr Nour

The increasing sophistication and complexity of Advanced Persistent Threats (APTs) pose significant challenges to security practitioners. To proactively protect against these threats, security practitioners rely on the generation of testflows, structured sequences of actions designed to verify whether the tactics and behaviors of an APT are present within their organization. However, manually creating such testflows is time-consuming, error-prone, and highly dependent on expert knowledge. Moreover, existing automated approaches suffer from several limitations, including validity, efficiency, and insufficient domain adaptation. To address these challenges, this paper introduces CTI-RAGFlow, to automate the generation of relevant, valid, and effective testflows from unstructured threat reports tailored to specific organizational environments. CTI-RAGFlow introduces three key contributions: (i) a dual-ontology approach, that integrates both a system ontology representing the operational environment and a cybersecurity ontology capturing adversary tactics, techniques, and procedures, improving the precision and accuracy of generated testflows; (ii) a fact-based context retrieval mechanism that combines a hypergraph structured knowledge base with a Retrieval-Augmented Generation pipeline using Large Language Models; and (iii) a fully automated testflow generation process that minimizes manual effort, reduces human error, and facilitates the generation of valid testflow. We evaluate CTI-RAGFlow against three widely used LLM models (e.g., base and fine-tuned models) using publicly available CTI reports for three well-known APTs (e.g., APT41, APT29, APT28). The results show that CTI-RAGFlow outperforms the baselines in terms of semantic relevance, coverage, validity, and effectiveness in verifying multi-stage cyberattack scenarios.

Ensuring cybersecurity in an ever-evolving threat landscape requires proactive identification and understanding of potential threats. Conventional detection and prediction solutions often fall short as they predominantly focus on known attack vectors. Advanced Persistent Threats (APTs) are becoming increasingly sophisticated and stealthy, resulting in new threat variants that are undetectable by these detection solutions. This paper introduces THREATIFY, a novel approach to predicting the most probable threat variants from existing APTs and previously seen attack campaigns. Our approach automates the generation of threat variants using graph-based machine learning based on the attack definition, past attack campaigns, and the security context between different techniques. THREATIFY leverages a security knowledge base of realistic attack scenarios and cybersecurity expertise to model, generate, and predict new forms of potential future threats by combining inter-(i.e. within the same APT attack) and intra-(i.e. between different APTs) techniques used by threat actors. It is crucial to emphasize that THREATIFY does not merely mix techniques from different APTs; rather, it constructs a logical and pragmatic kill chain based on their security context. THREATIFY is able to predict new attack steps, find relevant techniques to be substituted by, and merge APTs techniques in the current security context, and thus create previously unexplored threat variants. Our extensive experimental results demonstrate the efficacy of our approach in generating relevant and novel threat variants with a similarity score of 92%, uniqueness of 82%, validity of 95%, and reduction rate of 96%, including those that have never occurred before.

Due to the complex nature of Advanced Persistent Threats (APTs) and their rapid evolvement, comprehensive datasets are needed to understand them. However, acquiring such datasets remains a challenge due to the lack of precise reports describing the attacks, realistic emulation, the extensive attack diversity, and concerns regarding data privacy. In this paper, we built a testbed for APTs and implemented 23 campaigns for 12 APTs using MITRE Caldera. For each campaign, we share the adversary profile, the abilities, the low-level telemetries, and the MITRE techniques. By making this comprehensive dataset openly accessible, our work supports academia and industry to strengthen cybersecurity research and develop robust defenses against the constantly evolving APTs.

In this article, we present ThreatScout, an automated threat hunting solution leveraging machine reasoning. Our evaluation on five threat actors shows hunting rates up to 92%, demonstrating ThreatScout’s effectiveness in automating threat hunting and enhancing proactive threat identification.

A large-scale cluster of containers managed with an orchestrator like Kubernetes are behind many cloud-native applications today. However, the weaker isolation provided by containers means attackers can potentially exploit a vulnerable container and then escape its isolation to cause more severe damages to the underlying infrastructure and its hosted applications. Defending against such an attack using existing attack detection solutions can be challenging. Due to the well known high false positive rate of such solutions, taking aggressive actions upon every alert can lead to unacceptable service disruption. On the other hand, waiting for security administrators to perform in-depth analysis and validation could render the mitigation too late to prevent irreversible damages. In this paper, we propose ACE-WARP, a cost-effective proactive and non-disruptive incident response to address such security challenges for Kubernetes clusters. First, our approach is proactive in the sense that it performs mitigation based on predicted (instead of real) attacks, which prevents irreversible damages. Second, our approach is also non-disruptive since the mitigation is achieved through live migration of containers, which causes no service disruption even in the case of false positives. Finally, to realize the full potential of this approach in containers migration, we formulate the inherent trade-off between security and cost (delay) as a multi-objective optimization problem. Our evaluation results show that ACE-WARP can successfully mitigate up to 81% of the attacks, and our optimization algorithm achieves up to 30% more threat reduction and 7% less delay while being 37 times faster compared to a standard optimization solution.

With the emergence of 5G networks and their large scale applications such as IoT and autonomous vehicles, telecom operators are increasingly offloading the computation closer to customers (i.e., on the edge). Such edge-core environments usually involve multiple Kubernetes clusters potentially owned by different providers. Confidentiality concerns could prevent those providers from sharing data freely with each other, which makes it challenging to perform common security tasks such as security verification across different clusters. In this work, we propose a solution for building cross-cluster security models to enable various security analyses, while preserving confidentiality for each cluster. We design a six-step methodology to model both the cross-cluster communication and cross-cluster event dependency, and we apply those models to different security use cases. We implement our solution based on a 5G edge-core environment that involves multiple Kubernetes clusters, and our experimental results demonstrate its efficiency (e.g., less than 8 seconds of processing time for a model with 3,600 edges and nodes) and accuracy (e.g., more than 96% for cross-cluster event prediction).

Threat hunting is a proactive security defense line exercised to uncover attacks that could circumvent conventional detection mechanisms. It is based on an iterative approach to generate, inspect, and revise attack hypotheses. The quality of these hypotheses is essential to prove/refute the existence of an attack. Today, attack hypotheses are often generated manually by security analysts. The generation process requires elusive expertise, is costly, and is prone to produce a large number of irrelevant hypotheses without considering the attack variants. In this paper, we address the aforementioned challenges by designing AUTOMA, a solution that automates the generation of relevant hypotheses and their variants using knowledge discovery. AUTOMA incorporates the system telemetry in combination with a knowledge base of existing attacks, techniques, and their relationships to mine the most relevant hypotheses. In order to increase the relevance of the generated hypotheses, AUTOMA examines these hypotheses by applying matching-based similarity, success, likelihood, and criticality evaluations. These evaluations are based on the past occurrences of the techniques part of a hypothesis in the system telemetry and the knowledge base. Additionally, AUTOMA uses sequence success, sequence alignment, and hierarchical similarity approach for generating potential attack variants of a hypothesis taking into account the dynamism and stealthiness of attackers in coming up with alternative attack steps. We extensively evaluate the effectiveness and efficiency of AUTOMA using a real dataset for 284 attack campaigns distributed over 57 advanced persistent threats. The obtained results show that AUTOMA is able to generate the relevant hypothesis (top 3), with a large reduction rate (up to 99%), and fast execution time (up to 8 minutes for proposing the relevant hypothesis and 10 seconds for variants generation).