Cinderella (B)

Alias:
Strain:-
detected when:
where:
Classification:COM-infector, resident
Length:402

Preconditions

Operating System(s):MS-DOS
Version/Release:All models
Computer model(s):PC's
Caroname:Cinderella.B

Attributes

Easy identification:

Type of Infection:

The virus overwrites the beginning of the file, appending the overwritten part after the end of the file. Selfrec in memory: Int21;ah=FB --> ah=00 Selfrec on disk: File[0] == 0FBB4h (MOV ah,0FBh)

Infection Technique:
Infection Trigger:(Open_RO || Load) && Filesize >= 390
Storage Media affected:
Interrupts hooked:21/3D00, 21/4B, 21/FB, 21/FC, 24, 16/00
Stealth:
Tunneling/Selfprot:
Oligo/Polymorphism:-
Encoding Method:
Damage:Transient: create a read-only hidden system file named "DDDDDDDD.DDF"(where "D" is 0DDh and "F" is 0FFh) and (probably) reset the computerby jumping to 0F000:E05Bh Permanent: -
Damage Trigger:Transient: Keypress && (Counter == 0) Permanent: -
Particularities:The virus resides in the interrupt vector table. The virus resides at the memory address: 0:200h Int80..IntE5 vectors are trashed. The counter is decremented at every keypress and incremented by 666each time a file is considered for infection. Int21;ah=FCh is used toexit into the host program. After infection but before closing thefile, the file date/time is read and immediately written again.
Similarities:

Agents

Countermeasures:
Standard means:

Acknowledgements

Location:Virus Test Center, University Hamburg, FRG
Classification by:Adam David, Frisk Software International
Documentation by:Adam David, Frisk Software International
Date:26.7.93
Information Source:Caroentry (autom.converter by S.Freitag)

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