The Interesting Case of WSL for Payload Staging

This case study examines how Windows Subsystem for Linux 2 (WSL2) can be abused for payload staging and indirect command execution, describing architectural differences from WSL1 and the telemetry blind spots that let malicious activity appear as benign Windows processes (e.g., DllHost.exe). It details the three boundary crossing mechanisms (interop, /mnt/c 9P filesystem access, and isolated networking), demonstrates what defenders see and don’t see in SIEM/telemetry, and provides detection guidance including a Sigma rule to mitigate the gap.