What are the Trojan Horses?
This is software that claims to do one thing but actually does something very different and destructive. In the spring of 1997, a piece of software called AOL4FREE appeared on the Internet. This was supposed to be a PV version of a similar program with the same name that had appeared a few years earlier for the Apple Macintosh.
The Mac software was an AOL piracy program that gave people free access to the AOL Service. The PC software was really a Trojan horse and deleted all the information on the hard disks of any computer it was installed on.
Virus-checking software cannot spot a Trojan horse, because technically the program is not a true virus. As far as a virus checker is concerned, a Trojan horse looks like an ordinary piece of software and has none of the tell-that signs that give away a virus. The only way to avoid a Trojan horse like this is to watch out for rumours and announcements on the Internet. Software that is associated with piracy and other illegal activities is much more likely to cause trouble than ordinary software.11