Original URL: http://www.theregister.co.uk/2000/12/21/nasty_hybrid_virus_gift_unwraps/

Nasty hybrid virus gift unwraps on Xmas day

Kriz virus/ bymer worm party bundle

By John Leyden

Posted in Software, 21st December 2000 17:24 GMT

A mutation of a dangerous virus could render the computers of infected users inoperable this Christmas.

The hybrid virus has the capacity to wipe hard drives and attempt to wipe a computer's BIOS chip on its trigger date - Christmas Day.

On 25 December, the virus will attempt to flash the BIOS of a computer, preventing boot up and in most cases requiring a user to replace hardware. The virus will also begin overwriting files on all available drives and modify the critical operating system file, KERNEL32.DLL.

The virus/worm mutation combines the destructive payload of the Kriz virus with the highly infectious bymer worm. Both pieces of malicious code have been known about for some time with Kriz first appearing in August 1999. Protection from both of them is available from antivirus vendors - it is the combination of the two into a hybrid that is causing particular concern.

Andre Post, a researcher at Symantec's AntiVirus Research Centre, said: "A hybrid can be created when a virus attacks a computer that is already infected with another virus or worm. The result is usually a combination of the worst characteristics of the 'parents'."

Kriz itself is a slow-spreading virus, which infects Portable Executable (PE) Windows files, with a destructive payload similar to the CIH (or Chernobyl) virus, and bymer is a rapidly-spreading but benign worm. Together they make a hybrid which is both destructive and infectious.

Its not the first time hybrid malicious code has been created. Earlier this year, Symantec reported a hybrid of bymer with the FunLove virus.

Symantec has made a free detection and repair tool available here. Users are also advised to update their antivirus software with the latest virus definition files, which will detect the hybrid. ®

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