NTLM Brute Force on a Service Account

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	10 Minutes
Deduplication Period	1 Day
Required Data	XDR Agent
Detection Modules	Identity Analytics
ATT&CK Tactic	Credential Access (TA0006)
ATT&CK Technique	Brute Force (T1110)
Severity	Low

Description

A service account attempted to authenticate to a target using NTLM an excessive number of times in a short period.

• This may indicate a NTLM brute-force attack.

Attacker's Goals

The attacker attempts to gain access to the service accounts.

Investigative actions

Verify any successful authentication by the user account referenced by the alert, as these can indicate the attacker managed to guess the credentials.