OAuth2 Token Request to secureidentity.action from Non-Browser Process
Detects OAuth2 token requests scoped to Google's secureidentity.action, used for passkey/security-domain-secret operations. Chrome's own sync/passkey process routinely requests this scope from the browser, so those requests (identified by a Chrome User-Agent) are excluded. Remaining matches indicate the token request did not originate from the legitimate Chrome browser process (e.g. a non-browser client, script, or tool crafting the request directly), which is anomalous and warrants investigation for possible passkey/security-domain-secret abuse or token reuse across devices.
Sigma
