PH_Rule_ES_IMPORT_AWS_16
Enabled
An attempt was made to modify AWS EC2 snapshot attributes. Snapshots are sometimes shared by threat actors in order to exfiltrate bulk data from an EC2 fleet. If the permissions were modified, verify the snapshot was not shared with an unauthorized or unexpected AWS account.
5
Security
Defense Evasion
Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics’ techniques are cross-listed here when those techniques include the added benefit of subverting defenses.
https://attack.mitre.org/tactics/TA0005T1578.001
Modify Cloud Compute Infrastructure: Create Snapshot
An adversary may create a snapshot or data backup within a cloud account to evade defenses. By first Creating a Cloud Instance, mounting one or more created snapshots to that instance, and then applying a firewall policy that allows the adversary access to the created instance, an adversary can gain inbound and outbound SSH access.
https://attack.mitre.org/techniques/T1578/001Server
AWS CloudTrail via AWS_CLOUDTRAIL
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
Filter
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
eventType CONTAIN "AWS-CloudTrail-EC2-ModifySnapshotAttribute"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
accountId,user
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.
The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern
accountId = Filter.accountId,
user = Filter.user