AWS EBS Snapshot possible exfiltration
Goal
Detect the possible exfiltration of an EBS snapshot.
Strategy
This rule allows you to monitor CloudTrail and detect the following API calls within a 15 minute time window:
An attacker can create a EBS snapshot from the EBS volume and modify the permissions of the snapshot to allow it to be shared publicly or with another AWS account. Using an attacker-controlled account, a new EBS volume can be created from the snapshot and attached to an EC2 instance for analysis.
Triage and response
- Determine if
{{@userIdentity.arn}} should have made the API calls. - If the API call was not made by the user:
- Rotate user credentials.
- Determine what other API calls were made by the user.
- Remove any snapshot attributes generated by the user with the
aws-cli command modify-snapshot-attribute. - Begin your organization’s incident response process and investigate.
- If the API calls were made by the user:
- Determine if the user should be performing these API calls.
- If No, see if other API calls were made by the user and determine if they warrant further investigation.
Changelog
10 October 2022 - Updated query and severity.
