A computer program that hijacks the personal computers of ordinary home users in order to pass on pornographic web pages has been discovered by US researchers.

The program was discovered by independent computer expert Richard M Smith, who was investigating claims of an internet payment scam.

Analysis of the program, dubbed Migmaf, shows that it can turn a home PC into a temporary relay for adult web pages and unsolicited “spam” email. So far 2000 computers have been detected carrying the rogue code, a relatively small number. But experts warn that the discovery reflects a disturbing new trend.

Generally we’ve seen an increase in the number of Trojans horses exploiting home computers and opening backdoors,” says Graham Cluley, chief researcher at UK anti-virus company Sophos. In June a computer virus was found to convert home PCs into “open mail relays” that spammers use to forward their email.

“With this kind of open scheme it’s hard for us to predict what a Trojan will do,” Cluley told New Scientist. “Whether they use you as a middle man for pornographers or for sending spam is up to them.”

More here.