How I built a lightweight standalone behavioral anti-stealer to protect my Windows environment

Scidrow666 — Tue, 14 Jul 2026 17:19:16 +0000

Hey everyone,

Tired of bloated corporate solutions eating up hundreds of megabytes of RAM just to monitor active local connections, I decided to build a lightweight, standalone behavioral anti-stealer strictly focused on stopping modern infostealers (Lumma, RedLine, etc.) from exfiltrating local browser profiles.

The project is completely open-source (GNU GPL v3) and written in pure Python (compiled to a tight ~9MB standalone executable). No heavy signature databases, no cloud telemetry. It works purely on proactive local host and socket heuristics.

How the background thread guards the perimeter every 5 seconds:

Process Lineage (Parent PID) Validation: Traces back the owner of any active LISTEN or ESTABLISHED socket. If a protected Windows system binary is spawned by an unverified process running inside temporary user directories (Temp/AppData/Downloads), it flags it as a potential hollowing/injection attempt and terminates the branch.
Cryptographic Integrity: Maintains a strict local memory dictionary cache of verified process identity indicators (SHA-256) to prevent malicious files from using whitelist name-spoofing tactics.
Protected Storage Auditing: Checks open file descriptors. If an unverified process tries to lock or read Chrome's "Login Data" or Telegram's "tdata" session paths while simultaneously establishing an external network connection, it flags it for immediate termination.
CPU Execution Check (Anti-Sleep): Catches delayed-execution malware by analyzing zeroed CPU runtime execution metrics.

I ran a 24-hour stress test on an old Phenom II setup running Windows 10, and the memory caching layer keeps overhead at a rock-solid 0-2% CPU usage. It successfully managed and isolated background telemetry agents and invasive service connections in real-time.

My main architectural questions for the community:

Is a 5-second interval safe enough, or can modern infostealers complete a full DPAPI decrypt-and-dump cycle faster than that?
What are the edge cases under Windows where process lineage tracking might cause false detections on legitimate protected OS services?

The full implementation details and compiled binary are available for audit in my repository:
https://github.com/Scidrow666/scidrow-hunter

Thanks for any performance feedback!

DEV Community: Scidrow666

How I built a lightweight standalone behavioral anti-stealer to protect my Windows environment