Ada (computer virus)
|This article's lead section may not adequately summarize key points of its contents. (September 2016)|
|Aliases||Ada, Ada-2600, Ada.2600|
|Subtype||COM infector. Random nuisance.|
|Point of isolation||Unknown|
|Point of origin||Argentina|
|Author(s)||Pessoa , nome, feminino = Ada ( Feliz, Própera, Desfragmentar, Vírus) Brasil|
Ada virus was first discovered in Argentina in October, 1991. 
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:
- 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.
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.
- "ADA - Malware - McAfee Labs Threat Center". Vil.nai.com. Retrieved 2014-04-10.
- "ADA". McAfee. Retrieved 12 February 2013.