Introduction
Off-the-shelf traffic analysis tools are powerful but generic. When investigating specific protocol behaviors or hunting for subtle anomalies, custom tooling provides the precision needed.
Architecture
Our analysis pipeline consists of three stages: capture, parse, and analyze. Each stage is implemented as a standalone Python module communicating via Unix pipes.
Capture Layer
We use libpcap bindings for high-performance packet capture, with BPF filters to reduce noise at the kernel level.
Parser Layer
Protocol dissection is handled by a custom parser built on top of Scapy, extended with our own protocol definitions for proprietary protocols encountered during engagements.
Analysis Engine
The analysis engine applies configurable rule sets to parsed traffic, flagging anomalies based on statistical deviation from established baselines.
Results
In field testing, our toolchain identified three zero-day anomalies in a client’s network that commercial IDS solutions had missed, including an exfiltration channel disguised as DNS traffic.