Sunturai
Back to results
HighElastic detection rulesElastic

Entra ID Microsoft Authentication Broker Sign-In with Non-Standard User Agent

Detects Microsoft Entra ID sign-in activity where the Microsoft Authentication Broker authenticates is using a user agent that is not consistent with common browser, mobile, or Windows platform authentication…

Description

Detects Microsoft Entra ID sign-in activity where the Microsoft Authentication Broker authenticates is using a user agent that is not consistent with common browser, mobile, or Windows platform authentication clients. Adversary-in-the-middle and OAuth phishing tooling often presents scripted or relayed user agents (for example Node.js, Python, or generic HTTP libraries) while still targeting first-party resources through the broker.

Detection logic

Its licence does not clear it for publishing here

Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.

Sign in to read itCreate an account

Detection requirements

Platform
ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows

The rule states no platform. This is derived from the 3 ATT&CK techniques it maps to.

Log source category
event_index

Known benign triggers

  • Legitimate automation, SDKs, or custom applications that obtain tokens through the Microsoft Authentication Broker against Graph, Azure AD, or Device Registration Service may use non-browser user agents. Baseline approved service principals, managed identities, and developer tooling before tuning exclusions for known automation patterns.

Detections can measure how the public catalogue is used — which detections people look for, and which pages bring them here. It sets a cookie that recognises this browser for 180 days. It is never linked to an account and never follows you to other sites. Privacy notice