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AWSCloudTrail - S3 Object Exfiltration from Anonymous User

Description

Detects S3 GetObject activity performed by anonymous principals, which can indicate unauthorized object access and potential data exfiltration from public or misconfigured buckets.
Rule type
Scheduled
Version
1.0.1
Declared status
Available
Query frequency
5m
Query period
5m
Trigger
gt 0

Declared MITRE coverage

Declared sources

Metadata from the source file. No dependencies inferred from KQL.

Connectors

Data types

KQL query

Original query, unchanged.

AWSCloudTrail
| where ((UserIdentityAccountId =~ @'ANONYMOUS_PRINCIPAL' or UserIdentityPrincipalid == "Anonymous") and EventName == 'GetObject')
| extend
   BucketName = parse_json(RequestParameters).bucketName,
   ObjectKey = parse_json(RequestParameters).key
| extend UserName = substring(UserIdentityPrincipalid, indexof_regex(UserIdentityPrincipalid, ":") + 1)
| extend Name = split(UserName,'@')[0],UpnSuffix = split(UserName,'@')[1]

Declared entities

AccountIP

Related content

Links established from declared identifiers and solution manifests.

Source provenance

GitHub

Displayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.

Source identifier
15d3bf4e-8708-41c8-a836-8b0aa5be730e
Additional source files 2Solutions/Amazon Web Services/Analytic Rules/AWS_S3ObjectExfiltrationByAnonymousUser.yamlsource ↗Solutions/Amazon Web Services/Data/Solution_AmazonWebServices.jsonsolution-membership ↗
GSTEP / CATALOG TRACKING

Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC

GSTEP sync dates, separate from the source content’s publication dates.