They audited file permissions, ensuring only the SYSTEM and Administrators groups had write access to service binaries.
It may fail to launch services on Windows 10 Creators Update (or newer) unless AppNoConsole=1 is set in the registry.
: When the DaUM service restarts (either through a scheduled task, system reboot, or manual service restart), the malicious binary executes with the service's elevated privileges—typically LocalSystem or Administrator level. nssm-2.24 exploit
For defenders, the key takeaway is clear: NSSM is a legitimate and valuable administrative tool, but it must be treated with the same level of scrutiny as any other service management utility. Strict control over file permissions, careful service configuration, and proactive monitoring for unusual NSSM activity are essential to prevent this helpful tool from becoming a pathway for system compromise.
The NSSM-2.24 exploit works by abusing the nssm install command. When a user runs the command with a specially crafted configuration file, an attacker can inject malicious commands that are executed with elevated privileges. They audited file permissions, ensuring only the SYSTEM
Here's a step-by-step breakdown of the exploit:
Beyond formal CVEs, numerous threat intelligence reports have documented how to establish persistence and execute malicious payloads. In these cases, NSSM is not the “bug” but rather a powerful living‑off‑the‑land (LOLBin) tool that an adversary deploys after gaining initial access. For defenders, the key takeaway is clear: NSSM
Ensure that only SYSTEM and Administrators have write access to the directory where nssm.exe is stored.