Detection: gcp detect oauth token abuse

DEPRECATED DETECTION

This detection has been marked as deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported. If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2024-11-14 ID: a7e9f7bb-8901-4ad0-8d88-0a4ab07b1972 Author: Rod Soto, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

This search provides detection of possible GCP Oauth token abuse. GCP Oauth token without time limit can be exfiltrated and reused for keeping access sessions alive without further control of authentication, allowing attackers to access and move laterally.

1`google_gcp_pubsub_message` type.googleapis.com/google.cloud.audit.AuditLog 
2|table protoPayload.@type protoPayload.status.details{}.@type protoPayload.status.details{}.violations{}.callerIp protoPayload.status.details{}.violations{}.type protoPayload.status.message  
3| `gcp_detect_oauth_token_abuse_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name Value
google_gcp_pubsub_message sourcetype="google:gcp:pubsub:message"
gcp_detect_oauth_token_abuse_filter search *
gcp_detect_oauth_token_abuse_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1078 Valid Accounts Defense Evasion
Delivery
Exploitation
Installation
DE.AE
CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Risk Event False
This configuration file applies to all detections of type hunting.

Implementation

You must install splunk GCP add-on. This search works with gcp:pubsub:message logs

Known False Positives

GCP Oauth token abuse detection will only work if there are access policies in place along with audit logs.

Associated Analytic Story

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Not Applicable N/A N/A N/A
Unit ❌ Failing N/A N/A N/A
Integration ❌ Failing N/A N/A N/A

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

Source: GitHub | Version: 4