A malicious software program has infected the computers of more than 2,500 corporations around the world, according to NetWitness, a computer network security firm.

The malicious program, or botnet, can commandeer the operating systems of both residential and corporate computing systems via the Internet. Such botnets are used by computer criminals for a range of illicit activities, including sending e-mail spam, and stealing digital documents and passwords from infected computers. In many cases they install so-called “keystroke loggers” to capture personal information.

The current infection is modest compared to some of the largest known botnets. For example, a system known as Conficker, created in late 2008, infected as many as 15 million computers at its peak and continues to contaminate more than 7 million systems globally. Currently Shadowserver, an organization that tracks botnet activity, is monitoring 5,900 separate botnets. MORE....