Detection rules › Sigma

Malicious IP Address Sign-In Failure Rate

Status
test
Severity
high
Log source
product azure, service riskdetection
Author
Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
Source
github.com/SigmaHQ/sigma

Indicates sign-in from a malicious IP address based on high failure rates.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1090 Proxy

Rule body yaml

title: Malicious IP Address Sign-In Failure Rate
id: a3f55ebd-0c01-4ed6-adc0-8fb76d8cd3cd
status: test
description: Indicates sign-in from a malicious IP address based on high failure rates.
references:
    - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#malicious-ip-address
    - https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo'
date: 2023-09-07
tags:
    - attack.t1090
    - attack.command-and-control
logsource:
    product: azure
    service: riskdetection
detection:
    selection:
        riskEventType: 'maliciousIPAddress'
    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

selection

Stage 1: selection

selection:
    riskEventType: 'maliciousIPAddress'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
riskEventTypeeq
  • maliciousIPAddress