Polyboot.B
Also known as Wyx.C
Summary
Wyx.C (b) is a polymorphic virus that infects boot sectors on local hard disks and floppy disks. It carries no payload, but may destroy FAT32 partitions when infecting them.
Technical Details
Once activated Wyx.C (b) reduces the total memory available to DOS applications by 2 KB and then loads itself at the top of memory (at the 638K limit).
It then infects the Master Boot Record (MBR) and the Disk Boot Sector (DBS) of the first active partition on the local hard disk.
Wyx.C (b) is a memory-resident virus that checks periodically for uninfected boot sectors (using the timer interrupt which is activated about 18.7 times per second) on any floppy disk in drive A or on the local hard disk (MBR or DBS of first active partition).
Due to bugs in the virus it may:
Overwrite part of the display memory during execution. This may cause garbled data to appear at the top of the screen.
Damage or destroy FAT32 partitions when infecting them.
Strings
Wyx.C (b) contains the string:
20/01/2001 WYX
