Summary
The 'FakeFormat' is a trojan program. Being run it overwrites
boot sector and both FAT copies of diskette in drive A: assuming
that there's a 1.44 mb diskette is there. After that a diskette
boot sector contains a stub that will output:
This is a DATA disk only;
Insery system disk, press any key when ready.
The trojan waits for keypress and if CTRL + C combination is
pressed exits to system, otherwise it loops (starts ist code from
the beginning).
[Analysis: Alexey Podrezov, F-Secure]