Detection rules › Panther

IAM User Policy Attached with Administrator Access

Severity
informational
Compliance
CIS 1.1
Log types
AWS.CloudTrail
Reference
https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html
Source
github.com/panther-labs/panther-analysis

An IAM user policy was attached with Administrator Access, which could indicate a potential security risk.

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1078 Valid Accounts
PersistenceT1078 Valid Accounts
Privilege EscalationT1078 Valid Accounts
StealthT1078 Valid Accounts

Rule body yaml

AnalysisType: rule
Filename: aws_iam_attach_admin_user_policy.py
RuleID: "AWS.IAM.AttachAdminUserPolicy"
DisplayName: "IAM User Policy Attached with Administrator Access"
Enabled: true
CreateAlert: false
LogTypes:
  - AWS.CloudTrail
Reports:
  CIS:
    - 1.1
  MITRE ATT&CK:
    - TA0007:T1078
Severity: Info
Description: >
  An IAM user policy was attached with Administrator Access, which could indicate a potential security risk.
Runbook: Check if the user policy was attached by an authorized user. If not, investigate the user policy attachment.
Reference: https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html
Tests:
  - Name: IAM User Policy Attached with Administrator Access
    ExpectedResult: true
    Log:
      {
        "eventVersion": "1.05",
        "userIdentity":
          {
            "type": "AssumedRole",
            "principalId": "tester",
            "arn": "arn:aws:sts::123456789012:assumed-role/tester",
            "accountId": "123456789012",
            "accessKeyId": "1",
            "sessionContext":
              {
                "sessionIssuer":
                  {
                    "type": "Role",
                    "principalId": "1111",
                    "arn": "arn:aws:iam::123456789012:role/tester",
                    "accountId": "123456789012",
                    "userName": "Tester",
                  },
                "webIdFederationData": {},
                "attributes":
                  {
                    "mfaAuthenticated": "true",
                    "creationDate": "2019-01-01T00:00:00Z",
                  },
              },
          },
        "eventTime": "2019-01-01T00:00:00Z",
        "eventSource": "iam.amazonaws.com",
        "eventName": "AttachUserPolicy",
        "awsRegion": "us-west-2",
        "sourceIPAddress": "111.111.111.111",
        "userAgent": "console.amazonaws.com",
        "requestParameters":
          {
            "policyArn": "arn:aws:iam::aws:policy/AdministratorAccess",
            "userName": "new-user"
          },
        "responseElements": null,
        "requestID": "1",
        "eventID": "1",
        "readOnly": false,
        "eventType": "AwsApiCall",
        "recipientAccountId": "123456789012",
      }
  - Name: IAM User Policy Attached without Administrator Access
    ExpectedResult: false
    Log:
      {
        "eventVersion": "1.05",
        "userIdentity":
          {
            "type": "AssumedRole",
            "principalId": "tester",
            "arn": "arn:aws:sts::123456789012:assumed-role/tester",
            "accountId": "123456789012",
            "accessKeyId": "1",
            "sessionContext":
              {
                "sessionIssuer":
                  {
                    "type": "Role",
                    "principalId": "1111",
                    "arn": "arn:aws:iam::123456789012:role/tester",
                    "accountId": "123456789012",
                    "userName": "Tester",
                  },
                "webIdFederationData": {},
                "attributes":
                  {
                    "mfaAuthenticated": "true",
                    "creationDate": "2019-01-01T00:00:00Z",
                  },
              },
          },
        "eventTime": "2019-01-01T00:00:00Z",
        "eventSource": "iam.amazonaws.com",
        "eventName": "AttachUserPolicy",
        "awsRegion": "us-west-2",
        "sourceIPAddress": "111.111.111.111",
        "userAgent": "console.amazonaws.com",
        "requestParameters":
          {
            "policyArn": "arn:aws:iam::aws:policy/ReadOnlyAccess",
            "userName": "new-user"
          },
        "responseElements": null,
        "requestID": "1",
        "eventID": "1",
        "readOnly": false,
        "eventType": "AwsApiCall",
        "recipientAccountId": "123456789012",
      }

Detection logic

Condition

not (errorCode is_not_null or errorMessage is_not_null or eventName ne "AttachUserPolicy")
requestParameters.policyArn ends_with "AdministratorAccess"

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
errorCodeis_not_null(no value, null check)
errorMessageis_not_null(no value, null check)
eventNameneAttachUserPolicy

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
requestParameters.policyArnends_with
  • AdministratorAccess

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field
eventName
eventSource
awsRegion
recipientAccountId
sourceIPAddress
userAgent
userIdentity