ID | Technique | Tactic |
---|---|---|
T1490 | Inhibit System Recovery | Impact |
Detection: AWS Disable Bucket Versioning
Description
The following analytic detects when AWS S3 bucket versioning is suspended by a user. It leverages AWS CloudTrail logs to identify PutBucketVersioning
events with the VersioningConfiguration.Status
set to Suspended
. This activity is significant because disabling versioning can prevent recovery of deleted or modified data, which is a common tactic in ransomware attacks. If confirmed malicious, this action could lead to data loss and hinder recovery efforts, severely impacting data integrity and availability.
Search
1`cloudtrail` eventName= PutBucketVersioning "requestParameters.VersioningConfiguration.Status"=Suspended
2| stats count values(requestParameters.bucketName) as bucket_name values(resources{}.ARN) as resource_arn by src_ip aws_account_id awsRegion eventName userAgent user_arn userIdentity.principalId errorCode
3| `security_content_ctime(firstTime)`
4| `security_content_ctime(lastTime)`
5| `aws_disable_bucket_versioning_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
AWS CloudTrail PutBucketVersioning | AWS | 'aws:cloudtrail' |
'aws_cloudtrail' |
Macros Used
Name | Value |
---|---|
cloudtrail | sourcetype=aws:cloudtrail |
aws_disable_bucket_versioning_filter | search * |
aws_disable_bucket_versioning_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 | True |
Implementation
You must install splunk AWS add on and Splunk App for AWS. This search works with AWS CloudTrail logs.
Known False Positives
It is possible that an AWS Administrator has legitimately disabled versioning on certain buckets to avoid costs.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Bucket Versioning is suspended for S3 buckets- $bucket_name$ by user $user_arn$ from IP address $src_ip$ | 64 | 80 | 80 |
References
-
https://invictus-ir.medium.com/ransomware-in-the-cloud-7f14805bbe82
-
https://bleemb.medium.com/data-exfiltration-with-native-aws-s3-features-c94ae4d13436
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
Integration | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
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: 3