Moscow-based software developer Kaspersky Labs announced its detection of the malicious program this week. KaZaA’s peer-to-peer software is the most popular in the world, having been downloaded more than 81 million times, according to the figures of kazaa.com.
On an infected computer, the worm creates a directory accessible to other users of the KaZaA network and regularly copies itself into this directory under several thousand different names, each being the title of a popular song or movie.
When a KaZaA user conducts a search for a file under a name corresponding with one the worm's pseudonyms, the unsuspecting user is given the chance to download it from the infected computer, thus spreading the worm.
In addition to eating up free disk space and slowing down an infected computer’s operation, Benjamin opens an anonymous web site under the name of the infected computer's owner and uses it to display advertising banners, thus making money for Benjamin's creator.
Denis Zenkin, Kaspersky Labs’ Head of Corporate Communications, said:
"Benjamin is not the first known worm to exploit public access P2P file exchange networks. Previously, the Gnutella file exchange network fell victim to virus creators. This event once again demonstrates the necessity to filter all incoming files for viruses, regardless of how well protected this or any other network is. Before use, all data should be run through a mandatory check for virus code using the latest virus database update."