Hunting reverse shells: How the Sysdig Threat Research Team builds smarter detection rules

Sysdig’s Threat Research Team details the anatomy of TCP reverse shells, categorizing direct shell execution, indirect execution via IPC, and direct command execution variants, and mapping them to Linux syscalls, file descriptor handling, and IPC primitives. The article explains limitations of earlier detections and introduces improved Falco process STDIN/STDOUT/STDERR context fields and stateful observation rules to reliably identify multi-step reverse shell patterns while reducing false positives.