Classification

Category :

Malware

Type :

Virus

Aliases :

Wyx, Preboot

Summary

Wyx is a not dangerous memory resident encrypted boot virus. The virus code consists of two disk sectors. The virus infects the MBR of the hard drive, the C: drive boot sector and boot sector on floppy disks. The MBR of the hard drive gets infection on booting from an infected floppy disk. To infect other drives the virus hooks INT 8 (timer) and with delays checks if other drives are in use, and depending on that infects either drive A:, or drive B:, or boot sector if the C: drive.

While infecting the MBR sector the virus disables Virus protection by resetting necessary field in the CMOS memory. The original MBR, boot sector of the C: drive and second virus sector are stored in the last sectors of the hard drive first track (reserved track), the original boot sector of floppy drives is stored at the end of root directory sectors.

The virus does not manifest itself in any way. It contains the following text:

31/03/98 WYX
 

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

N/A