NTLM Brute Force

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	Informational

Description

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

• This may indicate an NTLM brute force attack.

Attacker's Goals

The attacker attempts to gain access to the 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.

Variations

NTLM brute force on a sensitive user

Synopsis

Field	Value
ATT&CK Tactic	Credential Access (TA0006)
ATT&CK Technique	Brute Force (T1110)
Severity	Medium

Description

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

• This may indicate an NTLM brute force attack.

Attacker's Goals

The attacker attempts to gain access to the 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.

High-frequency NTLM brute force attempts detected

Synopsis

Field	Value
ATT&CK Tactic	Credential Access (TA0006)
ATT&CK Technique	Brute Force (T1110)
Severity	Low

Description

A user account attempted to authenticate to a target using NTLM an excessive number of times and with high frequency.

• This may indicate an NTLM brute force attack.

Attacker's Goals

The attacker attempts to gain access to the 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.