AWS EC2 Instance Involved in Brute Force Attack

Classification:

attack

Tactic:

TA0006-credential-access

Technique:

T1110-brute-force

Set up the guardduty integration.

Overview

Goal

Detect Brute Force Attacks

Strategy

Leverage GuardDuty and detect when an attacker is performing a brute force attack. The following are GuardDuty findings trigger this signal:

• UnauthorizedAccess:EC2/SSHBruteForce
• UnauthorizedAccess:EC2/RDPBruteForce

Triage & Response

1. Inspect the role of the EC2 instance in the attack. Find the role in the signal name - either ACTOR or TARGET.
   • If you are the TARGET and the instance is available on the internet, expect to see IPs scanning your systems.
   • If you are the TARGET and the instance is not available on the internet, this means a host on your internal network is scanning your EC2 instance. Open an investigation.
   • If you are the ACTOR, this means that your instance is performing brute force attacks on other systems. Open an investigation.