Acid is a

computer virus A computer virus is a type of malware that, when executed, replicates itself by modifying other computer programs and Code injection, inserting its own Computer language, code into those programs. If this replication succeeds, the affected areas ...

which infects .COM and .

EXE Exe or EXE may refer to: * .exe, a file extension * exe., abbreviation for Executive (disambiguation)#Role, title, or function, executive Places * River Exe, in England * Exe Estuary, in England * Exe Island, in Exeter, England Transportation a ...

files including {{samp,

command.com COMMAND.COM is the default command-line interpreter for MS-DOS, Windows 95, Windows 98 and Windows Me. In the case of DOS, it is the default user interface as well. It has an additional role as the usual first program run after boot ( ini ...

. Each time an infected file is executed, Acid infects all of the .EXE files in the current directory. Later, if an infected file is executed, it infects the .COM files in the current directory. Programs infected with Acid will have had the first 792

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...

s of the host program overwritten with Acid's own code. There will be no file length increase unless the original host program was smaller than 792 bytes, in which case it will become 792 bytes in length. The program's date and time in the

DOS DOS (, ) is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible syste ...

disk directory listing will not be altered. The following text

strings String or strings may refer to: *String (structure), a long flexible structure made from threads twisted together, which is used to tie, bind, or hang other objects Arts, entertainment, and media Films * ''Strings'' (1991 film), a Canadian anim ...

are found in infected files: *"*.EXE *.COM .." *"Program too big to fit in memory" *"Acid Virus" *"Legalize

ACiD An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

and

Pot Pot may refer to: Containers * Flowerpot, a container in which plants are cultivated * Pottery, ceramic containers made from clay * Cooking pot, a type of cookware * Pot, a beer glass Places * Ken Jones Aerodrome, IATA airport code POT * ...

" *"By: Copyfright Corp-$MZU"

External links

Computer Viruses (A)
by Probert Encyclopedia

by McAfee DOS file viruses