Virus Name: Anti-D
V Status: Rare
Discovery: March, 1992
Symptoms: .COM file growth; TSR; interfers with keyboard
Eff Length: 945 Bytes
Type Code: PRsC - Parasitic Resident .COM Infector
Detection Method: ViruScan, F-Prot, AVTK, Sweep, ChAV,
IBMAV, NAV, NAVDX, VAlert, PCScan,
NShld, Sweep/N, LProt, Innoc, NProt, IBMAV/N,
Removal Instructions: Delete infected files
The Anti-D, or Xuxa-945, virus was submitted in March, 1992. It is
from Argentina. Anti-D is a memory resident infector of .COM files,
but it does not infect COMMAND.COM.
The first time a program infected with the Anti-D virus is
executed, Anti-D will install itself memory resident as a low
system memory TSR of 1,264 bytes. It will hook interrupts 09,
21, and F8.
Once the Anti-D virus is memory resident, it will infect .COM
files when they are executed. Infected programs will have a file
length increase of 945 bytes with the virus being located at the
beginning of the file. The program's date and time in the
DOS disk directory listing will not be altered. Two text strings
can be found in the viral code in infected programs:
Anti-D interfers with the usage of the "D" key on the system
keyboard, hence the virus' name.
Known variant(s) of Anti-D are:
Anti-D B: Functionally similar to the Anti-D virus described
above, this is a very minor variant.
Origin: Argentina July, 1992.