Detection: Windows SQL Server Startup Procedure

Updated Date: 2025-02-06 ID: 7bec7c5c-2262-4adb-ba56-c8028512bc58 Author: Michael Haag, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

This detection identifies when a startup procedure is registered or executed in SQL Server. Startup procedures automatically execute when SQL Server starts, making them an attractive persistence mechanism for attackers. The detection monitors for suspicious stored procedure names and patterns that may indicate malicious activity, such as attempts to execute operating system commands or gain elevated privileges.

Search

 1`wineventlog_application` EventCode=17135 
 2| rex field=EventData_Xml "<Data>(?<startup_procedure>[^<]+)</Data>" 
 3| rename host as dest 
 4| eval risk_score=case( match(lower(startup_procedure), "xp_
 5|sp_
 6|cmdshell
 7|shell
 8|exec"), 90, true(), 70 ) 
 9| eval risk_message="SQL Server startup procedure '".startup_procedure."' was launched on host ".dest 
10| stats count min(_time) as firstTime max(_time) as lastTime by dest EventCode startup_procedure risk_message risk_score 
11| `security_content_ctime(firstTime)` 
12| `security_content_ctime(lastTime)` 
13| `windows_sql_server_startup_procedure_filter`

Data Source

Name	Platform	Sourcetype	Source
Windows Event Log Application 17135	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Application'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_sql_server_startup_procedure_filter	`search *`

windows_sql_server_startup_procedure_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
T1505.001	SQL Stored Procedures	Persistence

Installation

DE.AE

CIS 10

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 Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

To successfully implement this detection, you need to be ingesting Windows Application Event Logs from SQL Server instances. The detection specifically looks for EventID 17135 which indicates startup procedure execution. Ensure proper logging is enabled for SQL Server startup events and that the logs are being forwarded to your SIEM.

Known False Positives

Legitimate startup procedures may be used by database administrators for maintenance, monitoring, or application functionality. Common legitimate uses include database maintenance and cleanup jobs, performance monitoring and statistics collection, application initialization procedures, and system health checks. To reduce false positives, organizations should document approved startup procedures, maintain an inventory of expected startup procedures, monitor for changes to startup procedure configurations, and create exceptions for known good procedures.

Associated Analytic Story

SQL Server Abuse

Risk Based Analytics (RBA)

Risk Message:

A SQL Server startup procedure "$startup_procedure$" was executed on host $dest$, which could indicate an attempt to establish persistence

Risk Object	Risk Object Type	Risk Score	Threat Objects
startup_procedure	other	70	No Threat Objects
dest	system	90	No Threat Objects

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Application`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Application`	`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: 1