ESTSAUTH/ESTSAUTHLIGHT/ESTSAUTHPERSISTENT Session Cookies Set Without Enrolled Device
Detects the presence of specific Microsoft Entra (formerly Azure AD) authentication session cookies (ESTSAUTH, ESTSAUTHPERSISTENT, ESTSAUTHLIGHT) in web proxy traffic. This activity is indicative of session cookie theft and potential replay attacks (Pass-the-Cookie) where an adversary attempts to authenticate to Microsoft services using stolen session material from an unauthorized or non-enrolled device.
Sigma
