AWS SAML Update identity provider

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Description

This search provides detection of updates to SAML provider in AWS. Updates to SAML provider need to be monitored closely as they may indicate possible perimeter compromise of federated credentials, or backdoor access from another cloud provider set by attacker.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2021-01-26
• Author: Rod Soto, Splunk
• ID: 2f0604c6-6030-11eb-ae93-0242ac130002

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1078	Valid Accounts	Defense Evasion, Persistence, Privilege Escalation, Initial Access

Kill Chain Phase

• Exploitation
• Installation
• Delivery

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`cloudtrail` eventName=UpdateSAMLProvider 
| stats count min(_time) as firstTime max(_time) as lastTime by eventType eventName requestParameters.sAMLProviderArn userIdentity.sessionContext.sessionIssuer.arn sourceIPAddress userIdentity.accessKeyId userIdentity.principalId 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
|`aws_saml_update_identity_provider_filter`

Macros

The SPL above uses the following Macros:

• cloudtrail
• security_content_ctime

aws_saml_update_identity_provider_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

• _time
• eventName
• eventType
• requestParameters.sAMLProviderArn
• userIdentity.sessionContext.sessionIssuer.arn
• sourceIPAddress
• userIdentity.accessKeyId
• userIdentity.principalId

How To Implement

You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.

Known False Positives

Updating a SAML provider or creating a new one may not necessarily be malicious however it needs to be closely monitored.

Associated Analytic Story

• Cloud Federated Credential Abuse

RBA

Risk Score	Impact	Confidence	Message
64.0	80	80	User $userIdentity.principalId$ from IP address $sourceIPAddress$ has trigged an event $eventName$ to update the SAML provider to $requestParameters.sAMLProviderArn$

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://www.cisa.gov/uscert/ncas/alerts/aa21-008a
• https://www.splunk.com/en_us/blog/security/a-golden-saml-journey-solarwinds-continued.html
• https://www.fireeye.com/content/dam/fireeye-www/blog/pdfs/wp-m-unc2452-2021-000343-01.pdf
• https://www.cyberark.com/resources/threat-research-blog/golden-saml-newly-discovered-attack-technique-forges-authentication-to-cloud-apps

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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