Bron: http://www.vnunet.com/News/1152735'Robin Hood' virus on the loose
By Iain Thomson [12-02-2004]
Nachi worm adds another string to its bow
A new variant of the Nachi worm is patching PCs that are vulnerable to MyDoom.A.
Nachi B, also known as Welchi, copies itself onto systems using the same flaw as MyDoom.A, as a file named 'Svchost.exe'.
It then attempts to delete MyDoom and downloads patches to fix the security hole.
Carole Theriault, security consultant at Sophos, said: "It's an interesting case - some kind of Robin Hood virus.
"We're seeing some spreading but it's not going too fast. We're hoping everyone with MyDoom would have stripped it out by now. If IT managers haven't updated by now they are way behind the curve."
Viruses to deal with viruses are nothing new. In the mid 1990s a boot sector virus called Chinese Fish attempted something similar by removing a virus called Stoned.
Nachi's first incarnation emerged last year as an attempt to patch the security hole exploited by the Blaster worm.
David Emm, product marketing manager at McAfee Security, explained that such code is a bad idea.
"I see code like this as a little bit of a blind; a ruse to calm people's fears," he said.
"Nachi A did not do a particularly good job at patching systems and this one doesn't look much better. At the end of the day it's still self-replicating code and that's a bad medium."
Infection rates are low so far, but an antivirus signature is under development.
Interessante ontwikkeling, zullen AV bedrijven dit systeem ook in gaan zetten? Behalve het ontwikkelen van Dat files ook een anti-virus ontwikkelen (en dat op zeer grote schaal verspreiden) dat er voor zorgt dat indien iemand het echte virus ontvangt hij daar immuum voor is?
In principe is het natuurlijk het beste als iedere wereldburger netjes zijn PC beveiligd met een up-to-date virusscanner, maar de praktijk leert dat dit niet mogelijk is. Of zou je er juist alleen maar meer hoax berichten van krijgen waardoor de virusmakers we hoax-antivirussen gaan maken? Lastige kwestie, naar welke situatie gaan we toe?