AWS CloudTrail GuardDuty Trusted IP Set Updates via CreateIPSet

Alerts on CloudTrail GuardDuty CreateIPSet events that add or update trusted IP address sets.

FreeUnreviewedSigmahighv1

aws-cloudtrail-guardduty-trusted-ip-set-updates-via-createipset-6e61ee20

title: AWS CloudTrail GuardDuty Trusted IP Set Updates via CreateIPSet
id: ae46d5c9-f0ca-48b8-8478-e6185dafbc7b
status: test
description: This rule flags CloudTrail events where GuardDuty creates an IP set for trusted addresses (eventSource guardduty.amazonaws.com with eventName CreateIPSet). Attackers can abuse trusted/allowlisted IP configurations to reduce visibility and suppress security alerts from targeted sources. The detection relies on CloudTrail records containing the GuardDuty event source and the CreateIPSet action.
references:
  - https://github.com/RhinoSecurityLabs/pacu/blob/866376cd711666c775bbfcde0524c817f2c5b181/pacu/modules/guardduty__whitelist_ip/main.py#L9
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/aws/cloudtrail/aws_guardduty_disruption.yml
author: faloker, Huntrule Team
date: 2020-02-11
modified: 2022-10-09
tags:
  - attack.defense-impairment
  - attack.t1685
logsource:
  product: aws
  service: cloudtrail
detection:
  selection_source:
    eventSource: guardduty.amazonaws.com
    eventName: CreateIPSet
  condition: selection_source
falsepositives:
  - Valid change in the GuardDuty (e.g. to ignore internal scanners)
level: high
license: DRL-1.1
related:
  - id: 6e61ee20-ce00-4f8d-8aee-bedd8216f7e3
    type: derived

What it detects

This rule flags CloudTrail events where GuardDuty creates an IP set for trusted addresses (eventSource guardduty.amazonaws.com with eventName CreateIPSet). Attackers can abuse trusted/allowlisted IP configurations to reduce visibility and suppress security alerts from targeted sources. The detection relies on CloudTrail records containing the GuardDuty event source and the CreateIPSet action.

Known false positives

Valid change in the GuardDuty (e.g. to ignore internal scanners)

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