Both and have published advisories about the Trojan.

Energizer said it has removed the software from its download site, and added that although it had offered similar software for Mac OS X, only the Windows version had been infected.

This isn't the first time that a hardware company has planted malware on unsuspecting customers' PCs. In 2007, Seagate Technology admitted that an unknown number of its hard drives left an Asian manufacturing plant with Trojan horses, while the year before that that some of the music players carried a Windows .

In early 2008, electronic retailer Best Buy confirmed it had sold that spread to connected PCs.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at or subscribe to . His e-mail address is .