AIDS (computer virus)
Encyclopedia
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 following screen.
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 byte
s 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.
Computer virus
A computer virus is a computer program that can replicate itself and spread from one computer to another. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability...
written in Turbo Pascal
Turbo Pascal
Turbo Pascal is a software development system that includes a compiler and an integrated development environment for the Pascal programming language running on CP/M, CP/M-86, and DOS, developed by Borland under Philippe Kahn's leadership...
3.01a which overwrites com
COM file
In many computer operating systems, a COM file is a type of executable file; the name is derived from the file name extension .COM. Originally, the term stood for "Command file", a text file containing commands to be issued to the operating system , on many of the Digital Equipment Corporation mini...
files. AIDS is the first virus known to exploit the MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
"corresponding file" vulnerability. In MS-DOS, if both foo.com and foo.exe
EXE
EXE is the common filename extension denoting an executable file in the DOS, OpenVMS, Microsoft Windows, Symbian, and OS/2 operating systems....
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 following screen.
ATTENTION I have been elected to inform you that throughout your process of collecting and executing files, you have accidentally ¶HÜ¢KΣ► [PHUCKED] yourself over: again, that's PHUCKED yourself over. No, it cannot be; YES, it CAN be, a √ìτûs [virus] has infected your system. Now what do you have to say about that? HAHAHAHAHA. Have ¶HÜÑ [PHUN] with this one and remember, there is NO cure for AIDS
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 byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
s 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
AIDS II (computer virus)
AIDS II is a companion computer virus, which infects COM files. It was first discovered in April 1990, and is a variant of AIDS. Unlike other generic file infectors, AIDS II was the first known virus to employ what could be called a "corresponding file technique" of infection so that the original...
appears a more elegant revision of AIDS. AIDS II also employs the corresponding file technique to execute infected code.
External links
- AIDS MS-DOS Virus, YouTube video of infection by Ripspawnguild