Local process connects to browser CDP debug port over loopback

Ethan Andrews@eandrews

•updated Jul 23, 2026•5•0•8

Detects a non-browser process establishing a loopback connection to a Chrome or Edge remote-debugging (CDP) endpoint. Malicious processes may abuse the Chrome DevTools Protocol to drive a headless browser, allowing the attacker to perform browser-based actions or use the browser as a covert C2 channel. This rule monitors for HTTP requests to /json/list/ or /devtools/ on 127.0.0.1 originating from processes other than chrome.exe or msedge.exe.