Detection rules › Sigma
Suspicious Browser Activity
Indicates anomalous behavior based on suspicious sign-in activity across multiple tenants from different countries in the same browser
Known false positives
- We recommend investigating the sessions flagged by this detection in the context of other sign-ins from the user.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | |
| Persistence | |
| Privilege Escalation | |
| Stealth |
Rule body
title: Suspicious Browser Activity
id: 944f6adb-7a99-4c69-80c1-b712579e93e6
status: test
description: Indicates anomalous behavior based on suspicious sign-in activity across multiple tenants from different countries in the same browser
references:
- https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#suspicious-browser
- https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
date: 2023-09-03
tags:
- attack.stealth
- attack.t1078
- attack.persistence
- attack.privilege-escalation
- attack.initial-access
logsource:
product: azure
service: riskdetection
detection:
selection:
riskEventType: 'suspiciousBrowser'
condition: selection
falsepositives:
- We recommend investigating the sessions flagged by this detection in the context of other sign-ins from the user.
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
riskEventType: 'suspiciousBrowser'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
riskEventType | eq |
| field:"azure_ad::risk_event_types" kind:eq value:"suspiciousBrowser" |