AWSCloudTrail - Privilege escalation with FullAccess managed policy

id: afb4191b-a142-4065-a0da-f721ee3d006c
name: AWSCloudTrail - Privilege escalation with FullAccess managed policy
description: |
  Detects successful attachment of AWS managed policies containing FullAccess permissions to users, roles, or
  groups, excluding admin-named policies. This action can rapidly expand privilege scope and should be reviewed
  as potential cloud privilege escalation.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: AWS
    dataTypes:
      - AWSCloudTrail
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - PrivilegeEscalation
  - Persistence
relevantTechniques:
  - T1098.003
query: |
  AWSCloudTrail
  | where  EventName in ("AttachUserPolicy","AttachRolePolicy","AttachGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | where tostring(parse_json(RequestParameters).policyArn) has "FullAccess" and tostring(parse_json(RequestParameters).policyArn) !has "Admin"
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
  | project TimeGenerated, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityUserName, SessionMfaAuthenticated, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, RequestParameters, UserIdentityArn, ResponseElements
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
      - identifier: CloudAppAccountId
        columnName: RecipientAccountId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIpAddress
customDetails:
  EventName: EventName
  EventSource: EventSource
  AWSRegion: AWSRegion
  UserIdentityArn: UserIdentityArn
alertDetailsOverride:
  alertDisplayNameFormat: 'AWS FullAccess managed policy attachment by {{AccountName}}'
  alertDescriptionFormat: 'Detected {{EventName}} from {{SourceIpAddress}} attaching FullAccess managed policy in account {{RecipientAccountId}}.'
version: 1.0.2
kind: Scheduled