AIDS (computer virus)

Computer virus
Fullname = AIDS
Common name = AIDS
Technical name = AIDS
Family = N/A
Aliases = AIDSB, AIDS-II, AIDS II, AIDS92, Hahaha, Taunt
Classification = Virus
Type = DOS
Subtype = COM to EXE infector. Corrupter.
IsolationDate = circa 1990 [Isolation date of AIDS is estimated to be near the time when AIDS was authored. The time that AIDS was authored is estimated to be sometime closely before the time AIDS derivatives were authored. The earliest known derivative of AIDS is [http://www.totallygeek.com/vscdb/index.php?a=s&p=0&vi=l&d=c&i=1155663024c7edb20165f74c8eaabb98924c9fff9b Leprosy] , authored in 1990. Thus, AIDS is believed to be authored and isolated in early 1990.]
Isolation = Unknown
Origin = Unknown
Author = Doctor Dissector of Corrupted Programming International

AIDS is a computer virus written in Turbo Pascal 3.01a which overwrites com files. AIDS is the first virus known to exploit the MS-DOS "corresponding file" vulnerability. In MS-DOS, if both foo.com and foo.exe exist, then foo.com will always be executed first. Thus, by creating infected com files, AIDS code will always be executed before the intended exe code.

When the AIDS virus activates, it displays the message:

In the message above, the word "AIDS" covers about half of the screen. The system is then halted, and must be powered down and rebooted to restart it.

The AIDS virus overwrites the first 13,952 bytes of an infected com file. Overwritten files must be deleted and replaced with clean copies (available if you have made backups) in order to remove the virus. It is not possible to recover the overwritten portion of the program.

The AIDS II virus appears a more elegant revision of AIDS. AIDS II also employs the corresponding file technique to execute infected code. Even more sophisticated is nVIR's use of an additional code resource after patching the jump table.

The AIDS virus is not to be confused with the Aids Info Disk/PC Cyborg Trojan.

Notes

References

* [http://vil.nai.com/vil/content/v_98148.htm AIDS virus] , by McAfee
* [http://www.probertencyclopaedia.com/L21.HTM Computer Viruses (A)] , by Probert Encyclopedia

External links

* [http://www.youtube.com/watch?v=G252lZkydbQ AIDS MS-DOS Virus] , YouTube video of infection by [http://www.youtube.com/user/Ripspawnguild Ripspawnguild]