LoFP LoFP / it's possible that a user has legitimately deleted a network acl.

Techniques

Sample rules

AWS Network Access Control List Deleted

Description

Enforcing network-access controls is one of the defensive mechanisms used by cloud administrators to restrict access to a cloud instance. After the attacker has gained control of the AWS console by compromising an admin account, they can delete a network ACL and gain access to the instance from anywhere. This search will query the AWS CloudTrail logs to detect users deleting network ACLs.

Detection logic

`cloudtrail` eventName=DeleteNetworkAclEntry requestParameters.egress=false 
| fillnull 
| stats count min(_time) as firstTime max(_time) as lastTime by user_arn userIdentity.principalId eventName requestParameters.egress src userAgent 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `aws_network_access_control_list_deleted_filter`

Cloud Network Access Control List Deleted

Description

Enforcing network-access controls is one of the defensive mechanisms used by cloud administrators to restrict access to a cloud instance. After the attacker has gained control of the console by compromising an admin account, they can delete a network ACL and gain access to the instance from anywhere. This search will query the Change datamodel to detect users deleting network ACLs. Deprecated because it’s a duplicate

Detection logic

`cloudtrail` eventName=DeleteNetworkAcl
|rename userIdentity.arn as arn  
| stats count min(_time) as firstTime max(_time) as lastTime values(errorMessage) values(errorCode) values(userAgent) values(userIdentity.*) by src userName arn eventName 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `cloud_network_access_control_list_deleted_filter`