SQL Slammer is a computer worm that caused a denial of service on some Internet hosts and dramatically slowed down general Internet traffic, starting at 05:30 UTC on January 25, 2003. It spread rapidly, infecting most of its 75,000 victims within ten minutes. So named by Christopher J. Rouland, the CTO of ISS, Slammer was first brought to the attention of the public by Michael Bacarella (see notes below). Although titled "SQL slammer worm", the program did not use the SQL language; it exploited a buffer overflow bug in Microsoft's flagship SQL Server and Desktop Engine database products, for which a patch had been released six months earlier in MS02-039. Other names include W32.SQLExp.Worm, DDOS.SQLP1434.A, the Sapphire Worm, SQL_HEL, W32/SQLSlammer and Helkern.