This virus was found from Portugal in August 1994. The virus stays resident in memory occupying 2208 bytes of memory, and infects all executed COM and EXE files (except very small ones).
The virus is variably encrypted. This kind of encryption is called oligomorphic.It changes between generations, but can still be found with a search string. The virus inserts dummy instructions to the decryption loop and changes the orders of needed instructions. Also registers are swapped between different generations.
The name of the infected program can be found underneath the encryption. After that the virus contains the following text:
Apocalipse 2.0 por M.A.C. Isto e um virus - afaste-se do computador, seno constipa-se ! Boa sorte nas reparac_es - nada esta perdido... Tambem, andavas a trabalhar demais - aproveita para descansar ! Lembra-te: coisas destas so ajudam a formar caracter - no, no precisas de agradecer, e um prazer ajudar... Voltarei... Preme uma tecla
Which, when translated to english, mean something along these lines:
Apocalypse 2.0 by M.A.C. This is a virus - go away from your computer, it has the flu! Good luck with the repairing - nothing is lost... Also, I don't want you to work too much - remember to rest! Incidents like this just make you a stronger person, right? No need to thank me, it is a please to help... I'll be back... Press any key
The virus uses directory-stealth, so the change in the file-size of infected files is not visible as long the virus is resident.
Virus marks infected files by adding 100 years to the date-stamp and setting the seconds field in time-stamp to 62. These changes are not visible in a normal dir-listing.
[Translation: Manuel Del Rio Furio, EICS Spain]
Disinfection & Removal
Description Created: Mikko Hypponen, F-Secure