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

Techniques

Sample rules

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`

AWS Network Access Control List Deleted

Description

The following analytic detects the deletion of AWS Network Access Control Lists (ACLs). It leverages AWS CloudTrail logs to identify events where a user deletes a network ACL entry. This activity is significant because deleting a network ACL can remove critical access restrictions, potentially allowing unauthorized access to cloud instances. If confirmed malicious, this action could enable attackers to bypass network security controls, leading to unauthorized access, data exfiltration, or further compromise of the cloud environment.

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`