Sigma rule: MSSQL Add Account To Sysadmin Role

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-998e68ccc916, updated 2024-06-26T00:00:00.000Z.

Rule

Title: MSSQL Add Account To Sysadmin Role
Status: test
Level: high
Author: Nasreddine Bencherchali (Nextron Systems)
Date: 2022-07-13
Modified: 2024-06-26
File: rules/windows/builtin/application/mssqlserver/win_mssql_add_sysadmin_account.yml
Commit: ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects when an attacker tries to backdoor the MSSQL server by adding a backdoor account to the sysadmin fixed server role

Log source

product: windows
service: application
definition: Requirements: MSSQL audit policy must be enabled in order to receive this event in the application log

Detection

selection:
    Provider_Name|contains: 'MSSQL' # Note: We use contains to account for other third party providers - See https://github.com/SigmaHQ/sigma/issues/4876
    EventID: 33205
    Data|contains|all:
        - 'object_name:sysadmin'
        - 'statement:alter server role [sysadmin] add member '
condition: selection

False positives (as the rule lists them)

Rare legitimate administrative activity

References

https://www.netspi.com/blog/technical/network-penetration-testing/sql-server-persistence-part-1-startup-stored-procedures/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/application/mssqlserver/win_mssql_add_sysadmin_account.yml

Sources and licences

SigmaHQ
"MSSQL Add Account To Sysadmin Role" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/application/mssqlserver/win_mssql_add_sysadmin_account.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License
Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: MSSQL Add Account To Sysadmin Role",
entity page, dataset version ref-998e68ccc916, updated 2024-06-26T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/08200f85-2678-463e-9c32-88dce2f073d1 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 08200f85-2678-463e-9c32-88dce2f073d1, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.