huntrule

Azure Entra suspicious browser risk events across multiple tenants and countries

Flags Azure suspicious browser risk events tied to anomalous sign-ins across tenants and countries from the same browser.

FreeReviewedSigma · High · v5
Product
azure
Service
riskdetection
Author
Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo' (SigmaHQ), DRL 1.1
Published
2023-09-03
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access → Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags risk events of type suspiciousBrowser in Azure Entra risk detection. It is intended to surface anomalous sign-in behavior where activity appears to span multiple tenants and originates from different countries within the same browser, which attackers may leverage to evade detection while reusing client context. Telemetry relies on risk detection events reporting riskEventType='suspiciousBrowser'.

Reporting behind it

Related detections9 linkedT1078 — drag to rearrange
Possible Next.js Middleware Auth Bypass via X-Middleware-Subrequest Header (CVE-2025-29927)
Suspicious Brutforce with Denied Access Due to Account Restrictions Policies (via security)
Suspicious Success Login Attempt on a Windows OpenSSH Server (via security)
Suspicious SQL Server - Connection Attempt Using a Disabled Account (via application)
Suspicious Lateral Movement Detection - Based on "special Groups" Feature (via security)
Suspicious Snowflake Anomalous Client Application Associated With UNC5537 (via cloud)
Malicious Network Login Performed to Multiple Targets (via security)
Malicious RDP Reconnaissance with Valid Credentials Performed on Multiple Hosts (via security)
Malicious Local Administrator Added by Atera RMM Agent
Azure Entra suspicious browser risk events across multiple tenants and countries
Pivot detection · T1078 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.