Windows: NTLMv1 Logon Between Client and Server

Rule ID

PH_Rule_SIGMA_1137

Default Status

Enabled

Description

Detects the reporting of NTLMv1 being used between a client and server. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/system/lsasrv/win_system_lsasrv_ntlmv1.yml

Severity

MITRE ATT&CK® Tactics

Defense Evasion

Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics’ techniques are cross-listed here when those techniques include the added benefit of subverting defenses.

https://attack.mitre.org/tactics/TA0005

MITRE ATT&CK® Techniques

T1550.002

Use Alternate Authentication Material: Pass the Hash

Adversaries may "Pass the hash" using stolen password hashes to move laterally within an environment, bypassing normal system access controls. Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. Valid password hashes for an account are captured using a Credential Access technique and can be used with PtH to authenticate as that user. Once authenticated, PtH may be used to perform actions on local or remote systems.

https://attack.mitre.org/techniques/T1550/002

Impacts

Server

Data Source

Windows System Log via OMI or FortiSIEM Agent

Detection

Correlation

Remediation Guidance

No remediation guidance specified

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.

Filter

SubPattern Definitions

SubPattern Name: Filter

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType="Win-System-LsaSrv-6038"

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID

hostName

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1

Incident Attribute Mapping

This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.

The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern

hostName = Filter.hostName

FortiSIEM Rules