Azure Network Security Group Open to the World

azure

Classification:

attack

Tactic:

TA0005-defense-evasion

Technique:

T1562-impair-defenses

Set up the azure integration.

Goal

Detect when an Azure network security group allows inbound traffic from all IP Addresses.

Strategy

This rule monitors Azure Activity logs for network changes and detects when the @evt.name has a value of MICROSOFT.NETWORK/NETWORKSECURITYGROUPS/WRITE, @properties.securityRules.properties.direction has a value of Inbound, @properties.securityRules.properties.access has a value of Allow, and @properties.securityRules.properties.sourceAddressPrefix has a value of either 0.0.0.0/0 OR *.

Triage and response

  1. Inspect which Virtual Machines are associated with this security group.
  2. Determine whether this security group and the VMs should permit inbound traffic from all IP addresses.