We present AutoTuneX, a system architecture design and implementation for users to interactively fine-tune large language models (LLMs) based on automated hyperparameter optimization particularly built around Bandit Limited Discrepancy Search. Next to a classical Graphical User Interface (GUI) our system features an agentic runtime to facilitate automated fine-tuning via chat.

Software-defined networking (SDN) is a centralized, dynamic, and programmable network management technology that enables flexible traffic control and scalability. SDN facilitates network administration through a centralized view of the underlying physical topology; tampering with this topology view can result in catastrophic damage to network management and security. To underscore this issue, we introduce Marionette, a new topology poisoning technique that manipulates OpenFlow link discovery packet forwarding to alter topology information. Our approach exposes an overlooked yet widespread attack vector, distinguishing itself from traditional link fabrication attacks that tamper, spoof, or relay discovery packets at the data plane. Unlike localized attacks observed in existing methods, our technique introduces a globalized topology poisoning attack that leverages control privileges. Marionette implements a reinforcement learning algorithm to compute a poisoned topology target, and injects flow entries to achieve a long-lived stealthy attack. Our evaluation shows that Marionette successfully attacks five open-source controllers and nine OpenFlow-based discovery protocols. Marionette overcomes the state-of-the-art topology poisoning defenses, showcasing a new class of topology poisoning that initiates on the control plane. This security vulnerability was ethically disclosed to OpenDaylight, and CVE-2024-37018 has been assigned.

We present a hybrid program analysis framework that automates the synthesis of stateful system call policies that describe admissible behaviors of containerized programs. Given a container image as input, the framework generates a reference policy that encodes a security automaton obtained by symbolically micro-executing the corresponding container's binary entrypoint under the constraints extracted from the container image metadata and environment.We demonstrate the utility and practicality of our approach by synthesizing security policies for 25 challenges in the DARPA Cyber Grand Challenge (CGC) corpus, 5 real-world containerized programs, including the widely used NGINX web server, and a complete microservice application from public benchmarks. We run each program or microservice using both benign and attack scenarios under the protection of a runtime policy monitor. Furthermore, we evaluate our approach by comparing our synthesized policies to those generated by four state-of-the-art system call specialization tools. Our results demonstrate that our techniques can scale to large programs and accurately extract concise reference application models for security monitoring.

Browser fingerprinting remains a topic of particular interest for both the research community and the browser ecosystem, and various anti-fingerprinting countermeasures have been proposed by prior work or deployed by browsers. While preventing fingerprinting presents a challenging task, modern fingerprinting techniques heavily rely on JavaScript APIs, which creates a choke point that can be targeted by countermeasures. In this paper, we explore how browser fingerprints can be generated without using any JavaScript APIs. To that end we develop StylisticFP, a novel fingerprinting system that relies exclusively on CSS features and implicitly infers system characteristics, including advanced fingerprinting attributes like the list of supported fonts, through carefully constructed and arranged HTML elements. We empirically demonstrate our system's effectiveness against privacy-focused browsers (e.g., Safari, Firefox, Brave, Tor) and popular privacy-preserving extensions. We also conduct a pilot study in a research organization and find that our system is comparable to a state-of-the-art JavaScript-based fingerprinting library at distinguishing devices, while outperforming it against browsers with anti-fingerprinting defenses. Our work highlights an additional dimension of the significant challenge posed by browser fingerprinting, and reaffirms the need for more robust detection systems and countermeasures.

Automated malware classification assigns unknown malware to known families. Most research in malware classification assumes that the defender has access to the malware for analysis. Unfortunately, malware can delete itself after execution. As a result, analysts are only left with digital residue, such as network logs or remnant artifacts of malware in memory or on the file system. In this paper, a novel malware classification method based on the Windows prefetch mechanism is presented and evaluated, enabling analysts to classify malware without a corresponding executable. The approach extracts features from Windows prefetch files, a file system artifact that contains historical process information such as loaded libraries and process dependencies. Results show that classification using these features with two different algorithms garnered F-Scores between 0.80 and 0.82, offering analysts a viable option for forensic analysis.

Machine learning approaches to classify malware by family save analysts valuable time during incident response. A key challenge for these approaches is selecting features that are robust against concept drift, which describes the change in malware over time. In this paper, we evaluate a dynamic feature set based on Windows handles (e.g., files, registry keys) for malware family classification. Specifically, we examine the features' vulnerabilities and evaluate their robustness against concept drift. We curated a novel dataset that simulates the manipulations that attackers may invoke on malware samples. We demonstrate improved robustness to concept drift over traditional API call-based features by training machine learning classifiers on malware collected in the wild, and testing the classifiers against samples that underwent manipulations. Further, we investigate time decay due to concept drift using temporally consistent evaluations that do not assume access to newer information. The evaluation shows that our features are robust against malware obfuscation. Furthermore, we empirically demonstrate how malware labeling conventions (malware type or family) can affect results, and make recommendations for dataset construction.

A data representation for system behavior telemetry for scalable big data security analytics is presented, affording telemetry consumers comprehensive visibility into workloads at reduced storage and processing overheads. The new abstraction, SysFlow, is a compact open data format that lifts the representation of system activities into a flow-centric, object-relational mapping that records how applications interact with their environment, relating processes to file accesses, network activities, and runtime information. The telemetry format supports single-event and volumetric flow representations of process control flows, file interactions, and network communications. Evaluation on enterprise-grade benchmarks shows that SysFlow facilitates deeper introspection into attack kill chains while yielding traces orders of magnitude smaller than current state-of-the-art system telemetry approaches-drastically reducing storage requirements and enabling feature-filled system analytics, process-level provenance tracking, and long-term data archival for cyber threat discovery and forensic analysis on historical data.

Vulnerability patch management remains one of the most complex issues facing modern enterprises; companies struggle to test and deploy new patches across their networks, often leaving myriad attack vectors vulnerable to exploits. This problem is exacerbated by enterprise server applications, which expose tremendous amounts of information about their security postures, greatly expediting attackers' reconnaissance incursions (e.g., knowledge gathering attacks). Unfortunately, current patching processes offer no insights into attacker activities, and prompt attack remediation is hindered by patch compatibility considerations and deployment cycles.

A filesystem capable of curtailing data theft and ensuring file integrity protection through deception is introduced and evaluated. The deceptive filesystem transparently creates multiple levels of stacking to protect the base filesystem and monitor file accesses, hide and redact sensitive files with baits, and inject decoys onto fake system views purveyed to untrusted subjects, all while maintaining a pristine state to legitimate processes. Our prototype implementation leverages a kernel hot-patch to seamlessly integrate the new filesystem module into live and existing environments. We demonstrate the utility of our approach with a use case on the nefarious Erebus ransomware. We also show that the filesystem adds no I/O overhead for legitimate users.

Recent years have witnessed a rampant use of domain generation algorithms (DGAs) in major botnet crimewares, which tremendously strengthens a botnet's capability to evade detection or takedown. Despite a plethora of existing studies on detecting DGA-generated domains in DNS traffic, remediating such threats still relies on vetting the DNS behavior of each individual device. Yet, in large networks featuring complicated DNS infrastructures, we often lack the capability or the resource to exhaustively investigate every part of the networks to identify infected devices in a timely manner. It is therefore of great interest to first assess the population distribution of DGA-bots inside the networks and to prioritize the remediation efforts. In this paper, we present BotMeter, a novel tool that accurately charts the DGA-bot population landscapes in large networks. Specifically, we embrace the prevalent yet challenging setting of hierarchical DNS infrastructures with caching and forwarding mechanisms enabled, whereas DNS traffic is observable only at certain upper-level vantage points. We establish a new taxonomy of DGAs that captures their characteristic DNS dynamics. This allows us to develop a rich library of rigorous analytical models to describe the complex relationships between bot populations and DNS lookups observed at vantage points. We provide results from extensive empirical studies using both synthetic data and real DNS traces to validate the efficacy of BotMeter.

The domain name system plays a vital role in the dependability and security of modern network. Unfortunately, it has also been widely misused for nefarious activities. Recently, attackers have turned their attention to the use of algorithmically generated domain names (AGDs) in an effort to circumvent network defenses. However, because such domain names are increasingly being used in benign applications, this transition has significant implications for techniques that classify AGDs based solely on the format of a domain name. To highlight the challenges they face, we examine contemporary approaches and demonstrate their limitations. We address these shortcomings by proposing an online form of sequential hypothesis testing that classifies clients based solely on the non-existent (NX) responses they elicit. Our evaluations on real-world data show that we outperform existing approaches, and for the vast majority of cases, we detect malware before they are able to successfully rendezvous with their command and control centers.

Many network visualizations make the assumption that an administrator has previously determined the subset of data that should be visualized. Yet the problem remains that if the visualization provides no insight into the network events that warrant further consideration, then the administrator must go back to the data to determine what should be visualized next. This is a critical issue given the amount of network data under consideration, only a small portion of which can be examined at any one time. In this paper we present a visualization that provides context for network visualizations by providing a high-level view of network events. Our visualization not only provides a starting point for network visualization, but also reduces the cognitive burden of the analyst by providing a visual paradigm for both the filtering of network data and the selection of network data to drill into and visualize with alternative representations. We demonstrate, through the use of a case study, that our visualization can provide motivation for further investigation into anomalous network activity.