Behavioral LOLBins detection engine with sequential correlation, PE masquerading checks, and Sysmon integration
9 November 2026 at 10:08
I built a behavioral detection engine focused on Living-off-the-Land binaries on Windows and wanted to share it with the community for feedback.
Problem it tries to solve
Traditional signature/hash-based detection struggles with LOLBins because they are legitimate, signed Microsoft binaries. Attackers also rename them, obfuscate command lines, and chain multiple utilities across time. Single-event rules often miss the broader operational context.
What the tool does
- Collects process telemetry (prefers Sysmon Event ID 1, falls back to psutil)
- Single-event behavioral rules for common LOLBins (certutil, bitsadmin, mshta, regsvr32, rundll32, powershell, wmic, etc.)
- Sequential multi-stage correlation (download β execute, LOLBin β encoded PowerShell, process cascades)
- Binary masquerading detection via PE OriginalFileName
- PPID spoofing anomaly checks
- Command-line obfuscation heuristics (carets, backticks, Base64 blocks, environment variable slicing)
- False-positive suppression + de-duplication
- Timeline reconstruction (Β±5β10 min window) + process lineage
- Local web dashboard for triage
- Automated Markdown incident reports + webhook support (Slack/Discord/SIEM)
Architecture highlights
- Modular pipeline: collector β correlation state machine β detection engine β timeline reconstructor β dispatcher
- Rules can be written in YAML (declarative) or pure Python
- Built-in threat emulation test harness (11 scenarios currently)
Current limitations
- psutil mode has polling latency (can miss very short-lived processes)
- Still user-mode only (no kernel/ETW consumer yet)
- Needs more real-world tuning of suppression rules
GitHub: https://github.com/nimesh895/Behavioral-Living-off-the-Land-LOLBins-Detection-System
Would love feedback on:
- Rule coverage / false positive rates youβve seen with similar approaches
- Missing high-value sequential chains
- Whether the dashboard and timeline reconstruction are useful in practice
- Any other LOLBins or techniques I should prioritize
Happy to answer technical questions or discuss design decisions.
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