Top 10 worst computer viruses

Worming their way in: computer viruses, worms and trojans have become more damaging and intrusive in the last ten years CREDIT: CLARE KENDALL

Around-up to the 10 worst computer viruses of all time.

Malicious software, worms, Trojans and computer viruses are on the increase, say security experts, as hackers, spammers and identity thieves seek new ways to steal information that can be used to empty bank accounts or spread electronic mayhem. Here, we present a look back at the 10 worst computer viruses of ever made:

1. The Morris worm

In 1998 Robert Morris, a university student, unleashed a worm which affected 10 per cent of all the computers connected to the internet (at the time the net was estimated to consist of 60,000 computers), slowing them down to a halt. Morris is now an associate professor at MIT.