New Virus Fights Off Hackers

A new virus has hit the web - but it's a helpful one. The virus - a "cheese worm" - is making its way around the web, checking computers for vulnerabilities and closing them. It targets computers running Linux that have been attacked by a similar, but malign, program earlier this year (01). As it grows in popularity, Linux is increasingly being targeted by virus writers and malicious hackers. But the benevolent program has not been welcomed by anti-virus companies, who say any software that makes unauthorised changes to a computer is potentially dangerous. In March this year, a malicious program known as the Lion worm was infecting Linux servers and installing backdoors that could be exploited by its creators. The worm also stole passwords and sent them to those system crackers using it as an intrusion tool. The backdoors could be used to stage denial-of-service attacks that use a series of remotely commanded computers to bombard a target server with bogus requests. Usually, the target is overwhelmed by the stream of useless data and either crashes, or becomes unreachable by legitimate users. Although viruses that exploit the weaknesses of Microsoft Windows are by far the most numerous, some malicious hackers have started to target the increasingly popular Linux software. This year, four viruses, the Ramen, Lion, Adore and Sadmind/IIS worms, have been written to attack this software.