Virus Name:  AIDS II 
 Aliases:     Companion Virus 
 V Status:    Endangered 
 Discovery:   April, 1990 
 Symptoms:    Creates .COM files; melody; message 
 Eff Length:  8,064 Bytes 
 Type Code:   SNA - Spawning Non-Resident .COM & .EXE Infector 
 Detection Method:  ViruScan, NAV, F-Prot, AVTK, Sweep, IBMAV, 
                    NAVDX, VAlert, PCScan, ChAV, 
                    NShld, Sweep/N, Innoc, AVTK/N, NProt, IBMAV/N, NAV/N, 
 Removal Instructions:  Delete corresponding .COM files 
 General Comments: 
       The AIDS II virus, or Companion virus, was isolated for the first 
       time in April 1990.  Unlike other generic file infectors, the AIDS 
       II virus is the first known virus to employ what could be called a 
       "corresponding file technique" of infection so that the original 
       target .EXE file is never changed.  The virus takes advantage of the 
       DOS feature where if a program exists in both .COM and .EXE form, 
       the .COM file will be executed. 
       The AIDS II virus does not actually infect .EXE files, instead it 
       stores a copy of the virus in a corresponding .COM file which will 
       be executed when the user tries to execute one of his .EXE files. 
       The .EXE file and the .COM file will both have the same base file 
       The method of infection is as follows:  when an "infected" program 
       is executed, since a corresponding .COM file exists, the .COM file 
       containing the viral code is executed.  The virus first locates an 
       uninfected .EXE file in the current directory and creates a 
       corresponding (or companion) .COM file with the viral code.  These 
       .COM files will always be 8,064 Bytes in length with a file 
       date/time of the date/time of infection.  The .EXE file is not 
       altered at all.  After creating the new .COM file, the virus then 
       plays a melody and displays the following message: 
                 "Your computer is infected with ... 
                            Aids Virus II  
                  - Signed WOP & PGT of DutchCrack -" 
       The AIDS II virus then spawns to the .EXE file that was attempting 
       to be executed, and the program runs without problem.  After 
       completion of the program, control returns to the AIDS II virus. The 
       melody is played again with the following message displayed: 
                        "Getting used to me? 
                    Next time, use a Condom ....." 
       Since the original .EXE file remains unaltered, CRC checking 
       programs cannot detect this virus having infected a system. 
       One way to manually remove the AIDS II virus is to check the disk 
       for programs which have both an .EXE and a .COM file, with the .COM 
       file having a length of 8,064 bytes.  The .COM files thus identified 
       should be erased. 
       The displayed text strings do not appear in the viral code. 

Show viruses from discovered during that infect .

Main Page