Research release · 2026

Agentic LLMs for Network Attack Detection

Can a tool-using LLM agent independently investigate a raw network capture and identify an attack?

This benchmark evaluates an LLM acting as an autonomous packet analyst, rather than a classifier over precomputed features. Given only a PCAP path and natural-language descriptions of 11 possible attacks, the agent chooses and executes its own queries, adapts to successive observations, and returns one capture-level decision.

What was tested

Autonomy

The agent receives no packet summary, extracted flow features, or analyst assistance. Its tool calls and complete investigation trajectory are retained for inspection.

Traffic conditions

Low-background captures contain only the scenario traffic and the testbed's normal idle activity. Generated-high-background captures add substantially more benign traffic, making attack evidence harder to isolate.

Matched benchmark

44 thirty-minute captures, six prompt variants, and 18 model/reasoning configurations produce 4,752 complete investigations.

Attack coverage 11 indicative classes

This mapping is for reader orientation only; these names were not shown to the LLM.

Attack 1
TCP ACK flood using IP fragmentation
Attack 2
ARP spoofing
Attack 3
DNS flood
Attack 4
FIN scan
Attack 5
ICMP fragmentation flood
Attack 6
NULL scan
Attack 7
TCP SYN port scan (nmap -sS)
Attack 8
Slowloris
Attack 9
UDP fragmentation flood
Attack 10
UDP scan
Attack 11
Xmas scan

Project resources

Authors

Matthieu Aureille ORCID LinkedIn

matthieu@aureille.org

Department of Computer Systems, Faculty of Information Technology, Czech Technical University in Prague; and Télécom Saint-Étienne, Jean Monnet University.

Suggested citation

If you use this benchmark, cite the canonical dataset release and reference the code repository.

M. Aureille and J. Fesl, “Agentic LLMs for Network Attack Detection,” version 1.0.0, Hugging Face dataset, 2026. [Online]. Available: https://huggingface.co/datasets/maureille/agentic-pcap

BibTeX
@misc{aureille2026agentic,
  author       = {Matthieu Aureille and Jan Fesl},
  title        = {Agentic LLMs for Network Attack Detection},
  year         = {2026},
  howpublished = {Hugging Face dataset},
  note         = {Version 1.0.0},
  url          = {https://huggingface.co/datasets/maureille/agentic-pcap}
}

Licenses

CC BY 4.0

PCAPs, dataset metadata, prompts, recorded sessions, decisions, result data, and figures.

MIT

Benchmark software and the HTML, CSS, and JavaScript used to present this site and dashboard.

Apache 2.0

The two mirrored third-party Gemma 4 chat templates retain their upstream license.