
     BAT.Batalia6

     -----------------------------------------------------------------
     It is a harmless nonmemory resident polymorphic parasitic BAT
     virus. It searches for BAT files in the current directory, then
     infects them. While infecting a file the virus runs the ARJ
     archiver to pack the necessary files. If there are no ARJ.EXE
     file in PATH, the virus fails to replicate itself.

     The infected contains two parts of code and data. The first part
     (the header) contains five DOS commands, the second part (the
     rest) contains a random named BAT file that is compressed by
     using the ARJ archiver and a password. So, the infected file
     contains the text strings (DOS commands) and the binary data (ARJ
     archive).

     That BAT file also contains two parts: the main virus code (batch
     commands) and the compressed data. The compressed data contains
     several files: the host file, the virus data and code files. The
     infected files look as ARJ archive within ARJ archive:

     Infected BAT file:

      +--------------------+
      ŚBAT instructions    Ś - Header1, startup virus code
      Ś--------------------Ś
      Ś  ARJ archive:      Ś - Random named BAT file packed with ARJ
      Ś +----------------+ Ś
      Ś ŚBAT instructionsŚ Ś - Header2, main virus code
      Ś Ś----------------Ś Ś
      Ś Ś  ARJ archive:  Ś Ś - The set of files
      Ś Ś +------------+ Ś Ś
      Ś Ś ŚBATALIA6.BATŚ Ś Ś - Infection, polymorphic and random generator
      Ś Ś Ś            Ś Ś Ś   routines
      Ś Ś Śhostfile.BATŚ Ś Ś - The original host file
      Ś Ś ŚZAGL        Ś Ś Ś - Virus data file
      Ś Ś ŚRULZ        Ś Ś Ś - Virus data file
      Ś Ś ŚFINAL.BAT   Ś Ś Ś - Deletes the temporary files and subdirectory
      Ś Ś +------------+ Ś Ś
      Ś +----------------+ Ś
      +--------------------+

     Header1 contains five commands that are selected from several
     variants and have different lengths, for example:

      @echo off                           @EcHo OfF
      rem arj e %0 %compec% -g5           rem COMMAND.COM nul /carj x %0 -g1
      C:\COMMAND.COM nul /carj x %0 -g2   %comspec% nul /c arj e HOST.BAT -g3
      :nul arj x %0 -g7 C:\COMMAND.COM    :echo C:\COMMAND.COM nul /carj x %0
      w HOST.BAT                          i HOST.BAT

     The ARJ archive is encrypted with a random selected password, so
     the virus does not contain constant bytes, and as a result it is
     the first known polymorphic BAT virus.

     When executed, the virus (header1) runs ARJ archiver, extracts
     the second part (BAT file) and executes it. The code of second
     part creates the temporary directory, extracts the files from the
     second archive to the temporary directory, then runs the
     searching, infecting and polymorphic routines, then executed the
     host file and deletes the temporary files and temporary
     directory.

     The code of the virus contains only the text strings. There are
     the comments:

     : Death Virii Crew  &  Stealth Group World Wide
     :            P R E S E N T S
     :       First Mutation Engine for BAT !
     :              Without ASM !
     :      [BATalia6] & FMEB (c) by Reminder

     :              //         __                  _
     : +--------  /// ------+ ___     Magazine     _    for VirMakers
     : Ś+++-++- // // -+-+++Ś ___ ________________ _ ___________________ _ ________
     : Ś++ Ś Ś /////  Ś Ś ŚŚŚ  __ ___ ___ ___ ___ ___ ___ ___    Ś _ ___ _ ___ ___
     : Ś++ - +  ///// ++- ++Ś   _ _ _ __  __  _    _  __  _ _    _ _ _ _ _ _   _
     : +------ // // -------+   _ _ _ _   ___ ___  _  ___ ___     __ ___ _ ___ ____
     : GROUP  // // WORLDWIDE   _ _________________ _______________________________
     :
     : Box 10, Kiev   252148
     : Box 15, Moscow 125080
     : Box 11, Lutsk  263020
     :
     :               R E A D    I N F E C T E D    V O I C E
     :
     :                                             (c) by Reminder (May 22, 1996)