Detection rules › Splunk

ASL AWS Disable Bucket Versioning

Status
production
Severity
low
Group by
"actor.user.account.uid", "actor.user.uid", "api.operation", "api.request.data", "api.service.name", "cloud.provider", "cloud.region", "http_request.user_agent", "src_endpoint.ip", bucketName
Author
Patrick Bareiss, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

  • It is possible that an AWS Administrator has legitimately disabled versioning on certain buckets to avoid costs.

MITRE ATT&CK coverage

TacticTechniques
Impact

Telemetry coverage

Rules detecting the same action

These rules filter on the same operation.

Rule body

name: ASL AWS Disable Bucket Versioning
id: f32598bb-fa5f-4afd-8ab3-0263cc28efbc
version: 7
creation_date: '2022-10-04'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: Anomaly
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.
data_source:
    - ASL AWS CloudTrail
search: |-
    `amazon_security_lake` api.operation=PutBucketVersioning
      | spath input=api.request.data path=VersioningConfiguration.Status output=Status
      | spath input=api.request.data path=bucketName output=bucketName
      | search Status=Suspended
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY actor.user.uid api.operation api.service.name
           http_request.user_agent src_endpoint.ip actor.user.account.uid
           cloud.provider cloud.region api.request.data
           bucketName
      | rename actor.user.uid as user api.operation as action api.service.name as dest http_request.user_agent as user_agent src_endpoint.ip as src actor.user.account.uid as vendor_account cloud.provider as vendor_product cloud.region as vendor_region
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `asl_aws_disable_bucket_versioning_filter`
how_to_implement: The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
known_false_positives: It is possible that an AWS Administrator has legitimately disabled versioning on certain buckets to avoid costs.
references:
    - https://invictus-ir.medium.com/ransomware-in-the-cloud-7f14805bbe82
    - https://bleemb.medium.com/data-exfiltration-with-native-aws-s3-features-c94ae4d13436
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: Bucket Versioning is suspended for S3 buckets- $bucketName$ by user $user$ from IP address $src$
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - Suspicious AWS S3 Activities
    - Data Exfiltration
asset_type: AWS Account
mitre_attack_id:
    - T1490
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat

Stages and Predicates

Stage 1: search

`amazon_security_lake` api.operation=PutBucketVersioning

Stage 2: spath

| spath input=api.request.data path=VersioningConfiguration.Status output=Status

Stage 3: spath

| spath input=api.request.data path=bucketName output=bucketName

Stage 4: search

| search Status=Suspended

Stage 5: fillnull

| fillnull

Stage 6: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY actor.user.uid api.operation api.service.name
       http_request.user_agent src_endpoint.ip actor.user.account.uid
       cloud.provider cloud.region api.request.data
       bucketName

Stage 7: rename

| rename actor.user.uid as user api.operation as action api.service.name as dest http_request.user_agent as user_agent src_endpoint.ip as src actor.user.account.uid as vendor_account cloud.provider as vendor_product cloud.region as vendor_region

Stage 8: search

| `security_content_ctime(firstTime)`

Stage 9: search

| `security_content_ctime(lastTime)`

Stage 10: search

| `asl_aws_disable_bucket_versioning_filter`

Indicators

These rows show field, operator, and value matches.