How do the new Trojan horses piggyback on Sonys software?
The Sony software hides itself very well on a computer, but allows other software to use the same technique. Essentially it establishes a new rule at the level of the operating system that says any software that starts with the string of characters “$sys$” should be hidden from view. Virus writers quickly took pre-existing malicious software and put those characters at the beginning of the relevant code, making their work invisible on any computer that had the Sony copy protection installed.
