Ada (computer virus)

For other uses, see Ada (disambiguation).

Ada
Technical name	ADA
Alias	Ada, Ada-2600, Ada.2600
Type	DOS
Subtype	COM infector. Random nuisance.
Classification	Virus
Family	N/A
Origin	Argentina
Authors	Pessoa , nome, feminino = Ada ( Feliz, Própera, Desfragmentar, Vírus) Brasil

Ada is a computer virus that can affect any of the DOS operating systems. Ada was first discovered in 1991.

History

Ada virus was first discovered in Argentina in October, 1991.

Characteristics

Ada is a memory resident (stays in the memory of the computer it infects after the program it infected executes) virus that infects files. The Ada virus mainly targets .COM files, specifically COMMAND.COM.

Infected programs will have 2,600 bytes additional data inserted at the beginning of the file, and the file itself will contain the text strings:

• COMMAND.COM
• PCCILLIN.COM
• PCCILLIN.IMG
• HATI-HATI !! ADA VIRUS DISINI !!Delete

Computers infected with the Ada virus will often have a slow clicking sound emitting from their speakers; this clicking may sometimes change in pitch. Computers infected also may show a "Disk Full" error even if the disk still has space on it.

While infected with the Ada virus, system memory measured by the DOS CHKDSK decreases by 21,296 bytes to 21,312 bytes. The virus will reside in the memory after an infected file is run and will infect any other .COM files executed on the computer. It will also hijack interrupts 08, 13 and 21.

Infection route

There is only one way to infect a computer with the Ada virus; by executing an infected file. The infected file may come from a variety of sources: floppy disks, files downloaded from the Internet, and infected networks.