Sony seems to have configured some of its music CDs to install spyware on a user's hard drive. It's apparently intended as an anti-piracy measure. To make sure that, once it's installed, it isn't un-installed, it uses techniques that hide it from the operating system and from antivirus software.
New research from Mark Russinovich over at Sysinternals (the company I've blogged about before as the source a ton of excellent and free software utilities) indicates that Sony BMG has configured some of its music CDs to install antipiracy software that uses techniques typically employed by hackers and virus writers to hide the program from users and to prevent them from ever uninstalling it.
The CDs in question make use of a technique employed by software programs known in security circles as "rootkits," a set of tools attackers can use to maintain control over a computer system once they have broken in.
Of course, what a corporation invents, no matter how legitimate the use to which it's put, malware writers can copy.
In the comments, one user explains how to remove it.