RUSS McRee’s 4 September 2026 SANS Internet Storm Center diary examines numbat, an open-source tool from Perplexity AI for monitoring supported desktop, CLI, IDE and gateway AI agents. Written as a Go binary for macOS, Linux and Windows, it discovers installed agents, installs local monitoring hooks and records events, findings, indicators and enforcement decisions. By default, these are written to `~/.numbat/records.ndjson`. The tool includes detection categories covering secrets, exfiltration, execution, reconnaissance, privilege, lateral movement, persistence and tampering.
McRee tested the `recon.network_sweep` detector by prompting ClaudeCode to run an nmap scan. The activity was recorded as a finding associated with MITRE ATT&CK technique T1046, Network Service Discovery. Numbat can also selectively enforce rules, collect live events using OTLP/HTTP, ship data without an external shipper, create investigation packages with SHA-256 manifests, and produce read-only agent timelines. The diary presents this as an evaluation of the tool’s capabilities rather than evidence of a numbat vulnerability or confirmed attack.