Get Signin Token

Status: experimental
Severity: high
Log source: product aws, service cloudtrail
Author: Zach Mathis (@yamatosecurity)
Source: github.com/Yamato-Security/suzaku-rules

Generate a SigninToken that can be used to login to the the AWS Management Console. Attackers might access via a Federated identity (such as AWS SSO) to the Management Console.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1078.004` Valid Accounts: Cloud Accounts
Persistence	`T1078.004` Valid Accounts: Cloud Accounts
Privilege Escalation	`T1078.004` Valid Accounts: Cloud Accounts
Stealth	`T1078.004` Valid Accounts: Cloud Accounts

Telemetry coverage

Platform	Record / event type
AWS	CloudTrail event `GetSigninToken`: Retrieves a sign-in token used to grant console access to a federated user via the AWS federation endpoint.

Rules detecting the same action

These rules filter on the same operation.

Attempt To Get Signin Token (Sigma)

Rule body

title: Get Signin Token
id: dbd3daf6-4e63-4d58-ab76-5f91a18e42c5
status: experimental
description: |
    Generate a SigninToken that can be used to login to the the AWS Management Console.
    Attackers might access via a Federated identity (such as AWS SSO) to the Management Console.
references:
    - https://fwdcloudsec.org/assets/presentations/2024/europe/sebastian-walla-cloud-conscious-tactics-techniques-and-procedures-an-overview.pdf
    - https://securitylabs.datadoghq.com/articles/tales-from-the-cloud-trenches-unwanted-visitor/
    - https://traildiscover.cloud/#SignIn-GetSigninToken
author: Zach Mathis (@yamatosecurity)
date: 2025-04-23
modified: 2025-04-23
tags:
    - attack.credential-access
    - attack.t1078.004 # Valid Accounts: Cloud Accounts
logsource:
    product: aws
    service: cloudtrail
detection:
    selection:
        eventName: 'GetSigninToken'
    filter:
        errorCode: 'AccessDenied'
    condition: selection and not filter
falsepositives:
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
    eventName: 'GetSigninToken'

Stage 2: `not filter`

filter:
    errorCode: 'AccessDenied'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`errorCode`	eq	`AccessDenied`	`excludes:errorCode` `field:"errorCode" value:"AccessDenied"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`eventName`	eq	`GetSigninToken`	`field:"aws::eventName" kind:eq value:"GetSigninToken"`