Dark Avenger (Type A)

Alias:
Strain:Infiltrator
detected when:
where:
Classification:Linkvirus, Extending, not reset-resident
Length:1.Length (1128) on storage medium 2.Length (2000) in RAM

Preconditions

Operating System(s):AMIGA-DOS
Version/Release:OS > 1.3 (will probably crash under 1.3/1.2)
Computer model(s):All Amiga's without CPU-Cache
Caroname:Infiltrator.DarkAvenger.A

Attributes

Easy identification:-

Type of Infection:

Self-Identification method on disk: Checking branch command at first codehunk of infected File Self-Identification method in memory: Checking for a matchword ($A0A1) at hooked- vector location -2 Executable File infection: extending file by 1128 bytes Memory-resident, hooking DOS-Open-Vector Not reset-resident Infection preconditions: Disk valid 8 spare blocks free Filesize <= 100000 Filesize >= 2000 Codehunk - Size <= 32752 Memory for infection available HUNK_HEADER found HUNK_CODE found HUNK_RELOC32 found 101500 Bytes of Memory allocatable JMP or JSR is not the first command in the Codehunk Original-Code is overwritten - but will be restored and executed (virus restores the original file, so that integrity-checks of the executeable itself probably will fail)

Infection Technique:
Infection Trigger:Opening executeable file
Storage Media affected:All media
Interrupts hooked:DOS-VEC OPEN
Stealth:
Tunneling/Selfprot:
Oligo/Polymorphism:
Encoding Method:
Damage:Transient Damage: Sets the current Windowtitle to ' -=- The Dark Avenger -=-',0 Transient/Permanent damage: Can't handle all DOS-Requests correctly Crashes the System on some requests May "Infect" data-files matching to te infection preconditions Some files won't run after infection.
Damage Trigger:Random (Rasterbeam on startup of infected file)
Particularities:No Memory available on virus startup -> virus executes its code in not allocated area may cause a crash after quitting the infected program. Virus "trys" to work with lower operating-System versions - but the routine for that will probably almost always crash. Virus is encrypted with random Value from raster-beam. The programmer of this Virus has very poor programming abilities, his System very surely runs under OS2.04
Similarities:Most parts are similar to the Infiltrator-Virus

Agents

Countermeasures:All
Standard means:VT2.58

Acknowledgements

Location:Virus Test Center, University Hamburg, FRG
Classification by:S. Freitag
Documentation by:S. Freitag
Date:14.12.1993
Information Source:Reverse-analysis of Virus-Code, Heiner-Schneegold

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