GuardDuty Suppression Rules and Filters for False Positives

Quick Answer

A GuardDuty suppression rule is the right tool because it lets the security team filter out a very specific, already-verified pattern of false positives, in this case a particular finding type tied to a particular IAM user's ARN, without weakening detection anywhere else in the account. Because the rule can be scoped narrowly to the exact finding type and IAM user generating it, matching findings are automatically archived going forward, while GuardDuty continues surfacing that same finding type normally for every other user or resource. This precision is the key differentiator from the alternatives: disabling the finding type entirely would silence that detection capability account-wide, meaning a genuinely malicious IP triggering the same finding type against a different user would also go undetected, trading away real coverage to fix a narrow, already-understood false positive. Modifying IAM permissions has no effect on GuardDuty's detection logic, since GuardDuty analyzes behavior and threat intelligence rather than permission grants, and VPC Flow Log filters control what network data gets logged, not what GuardDuty reports as a finding. Whenever a scenario describes a confirmed, narrowly-scoped false positive that needs to be silenced without reducing detection elsewhere, look for a suppression mechanism scoped to the exact match criteria, rather than a blunt instrument like disabling an entire finding type.