WXYC

Alias:
Strain:-
detected when:
where:
Classification:DBR - infector
Length:2 kilobyte(s) AT TO paragraph(s) OF MEMORY

Preconditions

Operating System(s):MS-DOS
Version/Release:Only effective if active DBR is at cyl 0 hd 1 sector 1
Computer model(s):PC's
Caroname:WXYC

Attributes

Easy identification:

Type of Infection:

Bootsector infection. Selfrec in memory: none, loads on boot Selfrec on disk: CMP word ptr [06] after reading DBR/FBR

Infection Technique:
Infection Trigger:access of uninfected disk following activation
Storage Media affected:Harddisks, Disketts
Interrupts hooked:Int 13
Stealth:
Tunneling/Selfprot:
Oligo/Polymorphism:
Encoding Method:
Damage:Transient: none Permanent: none apparent
Damage Trigger:Transient: none Permanent: none
Particularities:Corruption of floppy disk root directoryDoes not maintain registers according to IBM spec so somesystems (e.g. Zenith DOS 3.31) will not boot properly("Invalid partition" error) Displayed text: "WXYC rules this roost!" when booted on with zerosin three LSB of timer tick byte (0:46Ch) Not displayed text: "JAM WXYC" (in DBR name space) Tries to bypass MBR detection schemes & DBR protection by goingblindly for most likely DBR location on boot (see Limitations).Propagates STONED error of allocating 2k in memory when only oneis needed.REPAIR: Boot from clean floppy, return cyl 0 hd 0 sec 3 to cyl 0 hd 1 sec 1Floppy: replace FBR, zero affected directory sector.
Similarities:

Agents

Countermeasures:
Standard means:

Acknowledgements

Location:Virus Test Center, University Hamburg, FRG
Classification by:Padgett Peterson
Documentation by:Padgett Peterson
Date:2 November, 1993
Information Source:Caroentry (autom.converter by S.Freitag)

(c) 1996 Virus-Test-Center, University of Hamburg