PIVOTPIPE loader drops nb_ payload files under Windows Temp

Ibrahim Saud@tektrix

•updated Sep 21, 2026•0•0•5

This rule detects the creation of multiple suspicious files within the \Windows\Temp\nb_ directory. The monitored filenames, such as 'agent.json', 'pk.der', 'sleepmask.o', and 'core.pak', are highly characteristic of post-exploitation toolkits, specifically those associated with beaconing, shellcode injection, or modular C2 agents. Detecting these files in temporary locations, especially when appearing in combination, strongly indicates potential adversary activity involving the staging and execution of malicious payloads.