AWS CloudTrail: Root User Credential Usage (UserIdentity.type=Root)

Alerts on CloudTrail activity performed by AWS account root credentials.

FreeReviewedSigma · Medium · v5

Product: aws
Service: cloudtrail
Author: vitaliy0x1 (SigmaHQ), DRL 1.1
Published: 2020-01-21
Updated: 2026-07-31

ATT&CK techniques

Initial Access → Defense Evasion

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
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 flags CloudTrail events where the acting principal is the AWS account root user (userIdentity.type set to Root), excluding events with eventType recorded as AwsServiceEvent. Root credentials provide maximum privileges, so their use can indicate account takeover attempts, privilege escalation, or persistence activity. The detection relies on CloudTrail telemetry, specifically userIdentity.type and eventType fields.

Reporting behind it

Related detections9 linkedT1078.004 — drag to rearrange

Suspicious Microsoft Entra Device Code Authentication Flow

Suspicious M365 Password Spraying via Azure PowerShell AppId from Quad7 Botnet

Suspicious AWS Instance Access or Export via SSH Key or Export Task

Suspicious Azure OpenAI Model Enumeration and Deployment Creation (via azure)

Suspicious Azure Cognitive Services Account Key Enumeration via ListKeys (via azure)

Malicious Business Email Compromise OAuth Application Sign-In via Entra ID Service Principal (via azure)

Suspicious AWS API Call from TruffleHog Credential Scanner User Agent

Suspicious Compute Instance Metadata Modification in GCP

Malicious JavaGhost Security Group Creation (via cloudtrail)

AWS CloudTrail: Root User Credential Usage (UserIdentity.type=Root)

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-root-user-activity-for-account-access-8ad1600d

title: "AWS CloudTrail: Root User Credential Usage (UserIdentity.type=Root)"
id: 48fcd35b-8655-492a-a024-2cc982eea159
status: test
description: This rule flags CloudTrail events where the acting principal is the AWS account root user (userIdentity.type set to Root), excluding events with eventType recorded as AwsServiceEvent. Root credentials provide maximum privileges, so their use can indicate account takeover attempts, privilege escalation, or persistence activity. The detection relies on CloudTrail telemetry, specifically userIdentity.type and eventType fields.
references:
  - https://docs.aws.amazon.com/IAM/latest/UserGuide/id_root-user.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/aws/cloudtrail/aws_root_account_usage.yml
author: vitaliy0x1, Huntrule Team
date: 2020-01-21
modified: 2022-10-09
tags:
  - attack.privilege-escalation
  - attack.initial-access
  - attack.persistence
  - attack.stealth
  - attack.t1078.004
logsource:
  product: aws
  service: cloudtrail
detection:
  selection_usertype:
    userIdentity.type: Root
  selection_eventtype:
    eventType: AwsServiceEvent
  condition: selection_usertype and not selection_eventtype
falsepositives:
  - AWS Tasks That Require AWS Account Root User Credentials https://docs.aws.amazon.com/general/latest/gr/aws_tasks-that-require-root.html
level: medium
license: DRL-1.1
related:
  - id: 8ad1600d-e9dc-4251-b0ee-a65268f29add
    type: derived

Convert

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

SplunkSPL