The following analytic identifies one source Ip failing to authenticate into the AWS Console with 30 unique valid users within 10 minutes. This behavior could represent an adversary performing a Password Spraying attack against an AWS environment tenant to obtain initial access or elevate privileges.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-09-27
- Author: Bhavin Patel
- ID: 71e1fb89-dd5f-4691-8523-575420de4630
Kill Chain Phase
- CIS 3
- CIS 5
- CIS 16
1 2 3 4 5 `cloudtrail` eventName=ConsoleLogin action=failure | bucket span=10m _time | stats dc(_raw) AS unique_accounts values(user_name) as tried_accounts by _time, src_ip, eventName, action, user_agent | where unique_accounts > 30 |`aws_unusual_number_of_failed_authentications_from_ip_filter`
The SPL above uses the following Macros:
aws_multiple_users_failing_to_authenticate_from_ip_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
You must install Splunk Add-on for AWS in order to ingest Cloudtrail. We recommend the users to try different combinations of the bucket span time and the tried account threshold to tune this search according to their environment.
Known False Positives
No known false postives for this detection. Please review this alert
Associated Analytic Story
|54.0||60||90||Multiple failed console login attempts against users $tried_accounts$ seen from $src_ip$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1