LoFP / network acl's may be created by a network administrator. verify whether the user identity should be making changes in your environment. network acl creations by unfamiliar users should be investigated. if known behavior is causing false positives, it can be exempted from the rule.

Techniques

• T1133
• T1562

Sample rules

AWS EC2 Network Access Control List Creation

• source: elastic
• technicques:
  • T1133
  • T1562

Description

Identifies the creation of an AWS EC2 network access control list (ACL) or an entry in a network ACL with a specified rule number. Adversaries may exploit ACLs to establish persistence or exfiltrate data by creating permissive rules.

Detection logic

event.dataset:aws.cloudtrail and event.provider:ec2.amazonaws.com and event.action:(CreateNetworkAcl or CreateNetworkAclEntry) and event.outcome:success