AWS CloudTrail: S3 Browser creating IAM LoginProfiles after querying GetLoginProfile

Flags CloudTrail IAM GetLoginProfile and CreateLoginProfile activity initiated by an S3 Browser user agent.

FreeReviewedSigma · High · v5

Product: aws
Service: cloudtrail
Author: daniel.bohannon@permiso.io (@danielhbohannon) (SigmaHQ), DRL 1.1
Published: 2023-05-17
Updated: 2026-07-31

ATT&CK techniques

Initial Access → Defense Evasion

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
- T1059.009Cloud API
Persistence
- T1078.004Cloud Accounts
Priv Esc
- T1078.004Cloud Accounts
Defense Evasion
- T1078.004Cloud Accounts
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies AWS CloudTrail activity where the S3 Browser user agent issues IAM GetLoginProfile and CreateLoginProfile requests. Attackers can use these actions to enumerate login-related configuration and establish persistence by creating new IAM LoginProfiles. Detection relies on CloudTrail records for iam.amazonaws.com events and matching the S3 Browser string in the user agent.

Reporting behind it

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AWS CloudTrail: S3 Browser creating IAM LoginProfiles after querying GetLoginProfile

Pivot detection · T1078.004 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

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

aws-cloudtrail-s3-browser-enumerating-iam-loginprofiles-and-creating-missing-pro-db014773

title: "AWS CloudTrail: S3 Browser creating IAM LoginProfiles after querying GetLoginProfile"
id: 3baa69a2-0ec3-446f-9038-367a718355cb
status: test
description: This rule identifies AWS CloudTrail activity where the S3 Browser user agent issues IAM GetLoginProfile and CreateLoginProfile requests. Attackers can use these actions to enumerate login-related configuration and establish persistence by creating new IAM LoginProfiles. Detection relies on CloudTrail records for iam.amazonaws.com events and matching the S3 Browser string in the user agent.
references:
  - https://permiso.io/blog/s/unmasking-guivil-new-cloud-threat-actor
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/aws/cloudtrail/aws_iam_s3browser_loginprofile_creation.yml
author: daniel.bohannon@permiso.io (@danielhbohannon), Huntrule Team
date: 2023-05-17
tags:
  - attack.execution
  - attack.persistence
  - attack.initial-access
  - attack.privilege-escalation
  - attack.stealth
  - attack.t1059.009
  - attack.t1078.004
logsource:
  product: aws
  service: cloudtrail
detection:
  selection:
    eventSource: iam.amazonaws.com
    eventName:
      - GetLoginProfile
      - CreateLoginProfile
    userAgent|contains: S3 Browser
  condition: selection
falsepositives:
  - Valid usage of S3 Browser for IAM LoginProfile listing and/or creation
level: high
license: DRL-1.1
related:
  - id: db014773-b1d3-46bd-ba26-133337c0ffee
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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