← All bot detection signals

2. Evasion, Debugger, & Anti-Stealth Traps

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

This signal is assessed with other independent session, browser, and network evidence. 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.

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