Analytics Story: Cloud Federated Credential Abuse

Date: 2021-01-26 ID: cecdc1e7-0af2-4a55-8967-b9ea62c0317d Author: Rod Soto, Splunk Product: Splunk Enterprise Security

Description

This analytical story addresses events that indicate abuse of cloud federated credentials. These credentials are usually extracted from endpoint desktop or servers specially those servers that provide federation services such as Windows Active Directory Federation Services. Identity Federation relies on objects such as Oauth2 tokens, cookies or SAML assertions in order to provide seamless access between cloud and perimeter environments. If these objects are either hijacked or forged then attackers will be able to pivot into victim's cloud environements.

Why it matters

This story is composed of detection searches based on endpoint that addresses the use of Mimikatz, Escalation of Privileges and Abnormal processes that may indicate the extraction of Federated directory objects such as passwords, Oauth2 tokens, certificates and keys. Cloud environment (AWS, Azure) related events are also addressed in specific cloud environment detection searches.

Detections

Name ▲▼	Technique ▲▼	Type ▲▼
AWS SAML Access by Provider User and Principal	Valid Accounts	Anomaly
AWS SAML Update identity provider	Valid Accounts	TTP
O365 Add App Role Assignment Grant User	Cloud Account, Create Account	TTP
O365 Added Service Principal	Cloud Account, Create Account	TTP
O365 Excessive SSO logon errors	Modify Authentication Process	Anomaly
O365 New Federated Domain Added	Cloud Account, Create Account	TTP
Detect Mimikatz Using Loaded Images	LSASS Memory, OS Credential Dumping	TTP
Detect Mimikatz Via PowerShell And EventCode 4703	LSASS Memory	TTP
Certutil exe certificate extraction	None	TTP
Registry Keys Used For Privilege Escalation	Image File Execution Options Injection, Event Triggered Execution	TTP

Data Sources

Name ▲▼	Platform ▲▼	Sourcetype ▲▼	Source ▲▼
AWS CloudTrail AssumeRoleWithSAML	AWS	`aws:cloudtrail`	`aws_cloudtrail`
AWS CloudTrail UpdateSAMLProvider	AWS	`aws:cloudtrail`	`aws_cloudtrail`
CrowdStrike ProcessRollup2	N/A	`crowdstrike:events:sensor`	`crowdstrike`
O365	N/A	`o365:management:activity`	`o365`
O365 Add app role assignment grant to user.	N/A	`o365:management:activity`	`o365`
O365 UserLoginFailed	N/A	`o365:management:activity`	`o365`
Sysmon EventID 1	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 12	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 13	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 7	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Windows Event Log Security 4688	Windows	`xmlwineventlog`	`XmlWinEventLog:Security`

References

Source: GitHub | Version: 1