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Description

This search provides detection of users with KMS keys performing encryption specifically against S3 buckets.

  • Type: Anomaly
  • Product: Splunk Security Analytics for AWS, Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel:
  • Last Updated: 2021-01-11
  • Author: Rod Soto, Patrick Bareiss Splunk
  • ID: 884a5f59-eec7-4f4a-948b-dbde18225fdc

ATT&CK

ID Technique Tactic
T1486 Data Encrypted for Impact Impact
`cloudtrail` eventName=CopyObject requestParameters.x-amz-server-side-encryption="aws:kms" 
| rename requestParameters.bucketName AS bucket_name, requestParameters.x-amz-copy-source AS src_file, requestParameters.key AS dest_file 
| stats count min(_time) as firstTime max(_time) as lastTime values(src_file) AS src_file values(dest_file) AS dest_file values(userAgent) AS userAgent values(region) AS region values(src) AS src by user 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
|`aws_detect_users_with_kms_keys_performing_encryption_s3_filter`

Associated Analytic Story

How To Implement

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

Required field

  • _time
  • eventName
  • requestParameters.x-amz-server-side-encryption
  • requestParameters.bucketName
  • requestParameters.x-amz-copy-source
  • requestParameters.key
  • userAgent
  • region

Kill Chain Phase

Known False Positives

bucket with S3 encryption

RBA

Risk Score Impact Confidence Message
15.0 30 50 User $user$ with KMS keys is performing encryption, against S3 buckets on these files $dest_file$

Reference

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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