arXiv subjects

Veronica Valeros

Publications and source records attributed to Veronica Valeros.

11 recordsLinked to original sources

arXiv2026

Improving LLM-Based SSH Honeypots Through Prompting and Fine-Tuning

LLM-based SSH honeypots often use closed cloud LLMs because they give strong shell realism, but cloud models create deployment problems. These include no stable versioning, provider-side changes, attacker-driven cost, and model decommissioning. Local open-weight models avoid these problems, but they usually perform worse and make mistakes that reveal the honeypot. These mistakes include malformed outputs, command echoing, inconsistent filesystem state, and AI-style artifacts. This paper studies how to improve and evaluate the shell emulation accuracy of local LLM-based SSH honeypots using prompt design and supervised fine-tuning. We fine-tune and evaluate eight models in total: the original fine-tuned GPT-3.5 model used in shelLM and seven open-weight local models, each compared to its base model. We also test how prompt structure transfers across model families. Using 34 automated unit tests that measure shell emulation accuracy in single-session and fresh-session settings, we find that prompt design has a large effect and that fine-tuning depends on dataset coverage. Fine-tuning on the original 112-conversation dataset does not improve aggregate pass rate, while an expanded dataset built from honeypot logs produces clearly stronger local models. Taken together, the results suggest that prompting and fine-tuning can each improve local LLM honeypots on their own, but their effects do not combine straightforwardly, since strong rule-based prompting and supervised adaptation can also conflict by addressing overlapping shell-behavior constraints.

cs.CR↗

arXiv2026

Slips: Behavioral Evidence Aggregation for Network Security

Network intrusion detection systems often analyze individual packets or flows, although malicious behavior may develop across many connections and over time. This may limit their ability to combine isolated detections into a coherent assessment of host behavior. Packet-level features may also be too low-level for complex AI-based detection, requiring additional processing to improve accuracy while maintaining a low false-positive rate. We present Slips, a network intrusion detection system that builds host-centered behavioral profiles and organizes activity into time windows. It uses a modular architecture in which independent modules report evidence rather than generating final alerts directly. Slips then accumulates this evidence into host-level decisions. We evaluate Slips against Suricata on an expert-labeled PCAP dataset. At the profile-time-window level, Slips achieved 83% higher recall and a 70% higher F1 score than Suricata, while neither system produced false positives. These results indicate that time-window-based evidence accumulation can produce context-aware decisions that better align with expert judgment.

cs.CR↗

arXiv2026

Decoys Cannot Go Everywhere: Mapping the Deception Surface in MITRE ATT&CK

Cyber deception research often assumes that a decoy can be placed wherever there is attacker behavior. This work tests that assumption across MITRE ATT&CK v18.1. We introduce a four-criterion rubric for infrastructure deception and apply it to all 250 ATT&CK techniques. The rubric evaluates whether a defender-controlled decoy can be placed, whether an attacker is likely to interact with it, what intelligence that interaction can yield, and whether the interaction reliably indicates malice. The resulting deception surface is sparse: only 80 techniques (32%) admit a decoy the attacker could plausibly reach. For the remaining 170 techniques, there is no defender-controlled asset in the attacker's path that can be fabricated as a decoy. Decoy placement across those 80 techniques falls into two patterns we call Sweep and Seek. In Sweep, the attacker moves broadly through assets in range and encounters the decoy as part of that activity. In Seek, the attacker looks for a specific kind of asset and interacts with a fabricated version of it. These patterns give a simple placement rule: a decoy must either sit on a sweep path or imitate a sought asset. We also show that decoys usually have useful intelligence potential, but whether an attacker interacts with them at all, and whether that interaction reliably indicates malice, both vary. We release the rubric, decision rules, and per-technique assessment as an auditable baseline for future deception research and deployment planning, and show that infrastructure decoys cannot be assumed to apply to all attacker behavior.

cs.CR↗

arXiv2026

AdvancedShelLM: A Stateful Multi-Agent LLM Honeypot for SSH Deception

LLM-based SSH honeypots can generate believable interactions, but evaluations indicate they remain somewhat identifiable to determined attackers, indicating the need for a better scaffolding. We present a new LLM-based honeypot design that uses a multi-agent, multi-LLM architecture to address the limitations of the previous shelLM LLM honeypot. Our honeypot, called AdvancedShelLM, uses two LLM agents, a Manager and a Worker, that better understand the commands while reducing incorrect responses and increasing deception. It implements an advanced permanent filesystem, allowing many simultaneous attackers to see the same changing files for the first time. It was evaluated with: (i) unit tests for generative capabilities, (ii) an AI attacker (ARACNE) to assess realism and deception, (iii) human attackers to assess its deceptive capability, and (iv) an Internet deployment to evaluate deception in real-world attacks. In unit test results, AdvancedShelLM achieved a pass rate of up to 99.02%. The AI attacker ARACNE had issues making a decision if the system is honeypot or not, but showed slight bias towards saying honeypot, even for a real Ubuntu shell. With human attackers, AdvancedShelLM deceived more humans than Cowrie, but had similar results as shelLM. The Internet deployment showed concrete evidence that the output of AdvancedShelLM can influence the behaviour of real-life attackers.

cs.CR↗

arXiv2026

Ghost Without Shell: Measuring Non-Interactive SSH Attacks on Honeypots

Cyber deception research has focused on improving honeypot deception capabilities to increase attacker engagement and extend their interactions to collect more and better intelligence. For SSH honeypots, this relies on the assumption that attackers log in, open a shell, and type. We tested whether this still held by deploying eleven SSH honeypots that served both interactive and non-interactive session requests for fifteen days. We collected 177,622 authenticated sessions and validated our results against an independent Cowrie dataset over the same time window. We found that 99.23% of sessions were non-interactive. Interactive sessions account for only 0.10%. The same pattern held in the comparative third-party dataset used for evaluation. This finding is important because a honeypot that focuses on interactive shells or evaluates success based on session length and the number of commands can miss most authenticated attacks and draw the wrong conclusions about what attackers do after login.

cs.CR↗

arXiv2025

VelLMes: A high-interaction AI-based deception framework

There are very few SotA deception systems based on Large Language Models. The existing ones are limited only to simulating one type of service, mainly SSH shells. These systems - but also the deception technologies not based on LLMs - lack an extensive evaluation that includes human attackers. Generative AI has recently become a valuable asset for cybersecurity researchers and practitioners, and the field of cyber-deception is no exception. Researchers have demonstrated how LLMs can be leveraged to create realistic-looking honeytokens, fake users, and even simulated systems that can be used as honeypots. This paper presents an AI-based deception framework called VelLMes, which can simulate multiple protocols and services such as SSH Linux shell, MySQL, POP3, and HTTP. All of these can be deployed and used as honeypots, thus VelLMes offers a variety of choices for deception design based on the users' needs. VelLMes is designed to be attacked by humans, so interactivity and realism are key for its performance. We evaluate the generative capabilities and the deception capabilities. Generative capabilities were evaluated using unit tests for LLMs. The results of the unit tests show that, with careful prompting, LLMs can produce realistic-looking responses, with some LLMs having a 100% passing rate. In the case of the SSH Linux shell, we evaluated deception capabilities with 89 human attackers. The results showed that about 30% of the attackers thought that they were interacting with a real system when they were assigned an LLM-based honeypot. Lastly, we deployed 10 instances of the SSH Linux shell honeypot on the Internet to capture real-life attacks. Analysis of these attacks showed us that LLM honeypots simulating Linux shells can perform well against unstructured and unexpected attacks on the Internet, responding correctly to most of the issued commands.

cs.CR↗

arXiv2025

ARACNE: An LLM-Based Autonomous Shell Pentesting Agent

We introduce ARACNE, a fully autonomous LLM-based pentesting agent tailored for SSH services that can execute commands on real Linux shell systems. Introduces a new agent architecture with multi-LLM model support. Experiments show that ARACNE can reach a 60\% success rate against the autonomous defender ShelLM and a 57.58\% success rate against the Over The Wire Bandit CTF challenges, improving over the state-of-the-art. When winning, the average number of actions taken by the agent to accomplish the goals was less than 5. The results show that the use of multi-LLM is a promising approach to increase accuracy in the actions.

cs.CR↗

arXiv2024

Towards Better Understanding of Cybercrime: The Role of Fine-Tuned LLMs in Translation

Understanding cybercrime communications is paramount for cybersecurity defence. This often involves translating communications into English for processing, interpreting, and generating timely intelligence. The problem is that translation is hard. Human translation is slow, expensive, and scarce. Machine translation is inaccurate and biased. We propose using fine-tuned Large Language Models (LLM) to generate translations that can accurately capture the nuances of cybercrime language. We apply our technique to public chats from the NoName057(16) Russian-speaking hacktivist group. Our results show that our fine-tuned LLM model is better, faster, more accurate, and able to capture nuances of the language. Our method shows it is possible to achieve high-fidelity translations and significantly reduce costs by a factor ranging from 430 to 23,000 compared to a human translator.

cs.CL↗

arXiv2023

LLM in the Shell: Generative Honeypots

Honeypots are essential tools in cybersecurity for early detection, threat intelligence gathering, and analysis of attacker's behavior. However, most of them lack the required realism to engage and fool human attackers long-term. Being easy to distinguish honeypots strongly hinders their effectiveness. This can happen because they are too deterministic, lack adaptability, or lack deepness. This work introduces shelLM, a dynamic and realistic software honeypot based on Large Language Models that generates Linux-like shell output. We designed and implemented shelLM using cloud-based LLMs. We evaluated if shelLM can generate output as expected from a real Linux shell. The evaluation was done by asking cybersecurity researchers to use the honeypot and give feedback if each answer from the honeypot was the expected one from a Linux shell. Results indicate that shelLM can create credible and dynamic answers capable of addressing the limitations of current honeypots. ShelLM reached a TNR of 0.90, convincing humans it was consistent with a real Linux shell. The source code and prompts for replicating the experiments have been publicly available.

cs.CR↗

arXiv2023

Towards a better labeling process for network security datasets

Most network security datasets do not have comprehensive label assignment criteria, hindering the evaluation of the datasets, the training of models, the results obtained, the comparison with other methods, and the evaluation in real-life scenarios. There is no labeling ontology nor tools to help assign the labels, resulting in most analyzed datasets assigning labels in files or directory names. This paper addresses the problem of having a better labeling process by (i) reviewing the needs of stakeholders of the datasets, from creators to model users, (ii) presenting a new ontology of label assignment, (iii) presenting a new tool for assigning structured labels for Zeek network flows based on the ontology, and (iv) studying the differences between generating labels and consuming labels in real-life scenarios. We conclude that a process for structured label assignment is paramount for advancing research in network security and that the new ontology-based label assignation rules should be published as an artifact of every dataset.

cs.CR↗

arXiv2023

Attacker Profiling Through Analysis of Attack Patterns in Geographically Distributed Honeypots

Honeypots are a well-known and widely used technology in the cybersecurity community, where it is assumed that placing honeypots in different geographical locations provides better visibility and increases effectiveness. However, how geolocation affects the usefulness of honeypots is not well-studied, especially for threat intelligence as early warning systems. This paper examines attack patterns in a large public dataset of geographically distributed honeypots by answering methodological questions and creating behavioural profiles of attackers. Results show that the location of honeypots helps identify attack patterns and build profiles for the attackers. We conclude that not all the intelligence collected from geographically distributed honeypots is equally valuable and that a good early warning system against resourceful attackers may be built with only two distributed honeypots and a production server.

cs.CR↗