Check out NGS Software SQLCrack
NGSSQLCrack is an innovative password cracking utility for Microsoft SQL Server 7 and 2000 that can assist enterprises in securing their infrastructures. NGSSQLCrack allows system administrators and security professionals to quickly scan systems for weak passwords that are susceptible to brute force attack, and guard against them. An handy tool if you are worried about the security in your network.
Check it out for yourself