Pathogen.SMEG

Alias:
Strain:-
detected when:
where:
Classification:COM and EXE infector
Length:7,856 BYTES

Preconditions

Operating System(s):MS-DOS
Version/Release:DOS>4.x
Computer model(s):PC's
Caroname:Pathogen.SMEG

Attributes

Easy identification:

Type of Infection:

The virus appends itself to the files Selfrec in memory: Int 21h func 18FF -> AX=e701h Selfrec on disk: Year+100

Infection Technique:
Infection Trigger:EXEC (int 21h func 4B)
Storage Media affected:
Interrupts hooked:21/18,4B,6C 13/ 20/
Stealth:
Tunneling/Selfprot:
Oligo/Polymorphism:the virus uses variable encryption with a variable decryptor.
Encoding Method:
Damage:Transient: Permanent: Random sector writes
Damage Trigger:Permanent: DayofWeek=Monday Time=17:00:00 (unverified)
Particularities:The virus uses INT3 for some of its functions Displayed text: As formatted below:"Your hard-disk is being corrupted, courtesy of PATHOGEN!Programmed in the U.K. (Yes, NOT Bulgaria!) [C] The Black Baron 1993-4Featuring SMEG v0.1: Simulated Metamorphic Encryption Generator!'Smoke me a kipper, I`ll be back for breakfast.....'Unfortunately some of your data won`t!!!!!",encryptedThis message is doubly encrypted. It is encrypted along with the bodyof the virus with the usual polymorphic decryption and then furtherencrypted with a simple NOT. The message remains in memory encrypted witha NOT. Not displayed text: "SMEG v0.1",encrypted but only with the initialencryption of the body of the virus. This string is visible in memory. This virus seems to be spreading rapidly in the UK. It is highlypolymorphic and uses a large number of irrelevant instructions betweenthe actual decypting code and uses a variety of techniques toimplement the transfer of control at the end of the loop.
Similarities:

Agents

Countermeasures:
Standard means:

Acknowledgements

Location:Virus Test Center, University Hamburg, FRG
Classification by:Wolfgang Stiller
Documentation by:Wolfgang Stiller
Date:1994-04-04
Information Source:Caroentry (autom.converter by S.Freitag)

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