toString Interrogation

Detection approach

Function.prototype.toString integrity violation detected. puppeteer-extra-plugin-stealth patches toString with a Proxy in _utils/index.js to hide its evasions. Real browsers have unmodified native toString functions.

How this helps detect bots

Collect this signal alongside session context, request metadata, and other independent indicators. A single anomaly is a lead, not a verdict; corroborating anomalies make automated traffic more likely.

Legitimate traffic to consider

Secure custom enterprise builds or local proxy tools overriding the toString method.