A malware distribution and attack kit sold commercially through
underground channels on the Internet has compromised hundreds of
thousands of systems in the past six months, including an epidemic of
infections that hit Italian Web servers this past weekend, according to
security and antivirus firms.

Known as Mpack, the kit consists of commercial-grade software
components written in the PHP Web programming language and apparently
sold by a group of Russian programmers. The software, which comes with
a year of support, was first mentioned in an analysis penned by antivirus firm Panda Software. In mid-May, Panda stated that the software had compromised at least 160,000 computers.

http://www.securityfocus.com/brief/529