Detection: Windows Local Administrator Credential Stuffing

Updated Date: 2024-09-24 ID: 09555511-aca6-484a-b6ab-72cd03d73c34 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects attempts to authenticate using the built-in local Administrator account across more than 30 endpoints within a 5-minute window. It leverages Windows Event Logs, specifically events 4625 and 4624, to identify this behavior. This activity is significant as it may indicate an adversary attempting to validate stolen local credentials across multiple hosts, potentially leading to privilege escalation. If confirmed malicious, this could allow the attacker to gain widespread access and control over numerous systems within the network, posing a severe security risk.

Search

1`wineventlog_security` EventCode=4625 OR EventCode=4624 Logon_Type=3 TargetUserName=Administrator 
2| bucket span=5m _time 
3| stats dc(Computer) AS unique_targets values(Computer) as host_targets by _time, IpAddress, TargetUserName, EventCode 
4| where unique_targets > 30 
5| `windows_local_administrator_credential_stuffing_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Windows Event Log Security 4624	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Security'`	N/A

Macros Used

Name	Value
wineventlog_security	`eventtype=wineventlog_security OR Channel=security OR source=XmlWinEventLog:Security`
windows_local_administrator_credential_stuffing_filter	`search *`

windows_local_administrator_credential_stuffing_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1110	Brute Force	Credential Access
T1110.004	Credential Stuffing	Credential Access

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT28

APT38

APT39

DarkVishnya

Dragonfly

FIN5

Fox Kitten

HEXANE

OilRig

Turla

Chimera

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

To successfully implement this search, you need to be ingesting Windows Event Logs from domain controllers as well as member servers and workstations. The Advanced Security Audit policy setting Audit Logon within Logon/Logoff needs to be enabled.

Known False Positives

Vulnerability scanners or system administration tools may also trigger this detection. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Local Administrator credential stuffing attack coming from $IpAddress$	56	70	80

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 3