AddUserToGroup
AWS
AddUserToGroup
Event
Adds an IAM user to a specified group, granting the user all permissions attached to that group.
Security Context
- Adding users to privileged groups is a common persistence technique that grants broad permissions while appearing as routine administration.
Log Source
CloudTrail
Sample Event
Adversarial. Draco — having compromised long-term creds — adds his own IAM user (draco) to a pre-existing Administrators group. This achieves the same outcome as AttachUserPolicy AdministratorAccess but is often less alarmed-on because group additions look like routine onboarding. Same-user privesc pattern (userIdentity.userName == requestParameters.userName) is the cleanest detection signal.
{ "eventVersion": "1.09", "userIdentity": { "type": "IAMUser", "principalId": "AIDADRAC0MALF0YBADGY", "arn": "arn:aws:iam::555123456789:user/draco", "accountId": "555123456789", "accessKeyId": "AKIADRAC0MALF0YEXAMP5", "userName": "draco", "sessionContext": { "attributes": { "creationDate": "2026-04-15T18:51:02Z", "mfaAuthenticated": "false" } } }, "eventTime": "2026-04-15T20:03:18Z", "eventSource": "iam.amazonaws.com", "eventName": "AddUserToGroup", "awsRegion": "us-east-1", "sourceIPAddress": "203.0.113.66", "userAgent": "aws-cli/1.18.147 Python/3.7.10 Linux/5.4.0-1045-aws botocore/1.18.6", "requestParameters": { "groupName": "Administrators", "userName": "draco" }, "responseElements": null, "requestID": "90000000-0000-4000-8000-000001101000", "eventID": "90000000-0000-4000-8000-000001101001", "readOnly": false, "eventType": "AwsApiCall", "managementEvent": true, "recipientAccountId": "555123456789", "eventCategory": "Management", "tlsDetails": { "tlsVersion": "TLSv1.3", "cipherSuite": "TLS_AES_128_GCM_SHA256", "clientProvidedHostHeader": "iam.amazonaws.com" }}MITRE ATT&CK Mapping
Tactics: Persistence Privilege Escalation
Techniques:
- T1098 — Account Manipulation — Adversaries may manipulate accounts to maintain and/or elevate access to victim systems. Account manipulation may consist of any action that preserves or modifies adversary access to a compromised account, such as modifying credentials or permission groups. These actions could also include accoun...