LoFP LoFP / a user with more than 20 failed authentication attempts in the span of 5 minutes may also be triggered by a broken application.

Techniques

Sample rules

AWS High Number Of Failed Authentications For User

Description

The following analytic identifies an AWS account with more than 20 failed authentication events in the span of 5 minutes. This behavior could represent a brute force attack against the account. As environments differ across organizations, security teams should customize the threshold of this detection.

Detection logic

`cloudtrail` eventName=ConsoleLogin action=failure 
| bucket span=10m _time 
| stats dc(_raw) AS failed_attempts values(src_ip) as src_ip values(user_agent) by _time, user_name, eventName, eventSource aws_account_id 
| where failed_attempts > 20 
| `aws_high_number_of_failed_authentications_for_user_filter`

Azure AD High Number Of Failed Authentications For User

Description

The following analytic identifies an Azure AD account with more than 20 failed authentication events in the span of 10 minutes. This behavior could represent a brute force attack against the account. As environments differ across organizations, security teams should customize the threshold of this detection.

Detection logic

 `azure_monitor_aad` category= SignInLogs properties.status.errorCode=50126 properties.authenticationDetails{}.succeeded=false 
| rename properties.* as * 
| bucket span=10m _time 
| stats count min(_time) as firstTime max(_time) as lastTime values(src_ip) as src_ip by user 
| where count > 20 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_high_number_of_failed_authentications_for_user_filter`