Virus Name: Cavaco
V Status: New
Discovery: January, 1996
Symptoms: .COM & .EXE growth;
decrease in available free memory
Eff Length: 1,470 Bytes
Type Code: PRhAK - Parasitic Resident .COM & .EXE Infector
Detection Method: NAV, NAVDX, IBMAV, ViruScan, VAlert, AVTK, F-Prot,
AVTK/N, NAV/N, IBMAV/N, NShld, Innoc
Removal Instructions: Delete infected files
The Cavaco virus was received in January, 1996. It appears to be
from Portugal. Cavaco is a memory resident infector of .COM and
.EXE files, including COMMAND.COM.
When the first Cavaco infected program is executed, this virus will
install itself memory resident at the top of system memory but below
the 640K DOS boundary, not moving interrupt 12's return. Available
free memory, as indicated by the DOS CHKDSK program from DOS 5.0,
will have decreased by 1,760 bytes. Interrupt 21 will be hooked by
the virus in memory. Also at this time, the virus will infect the
copy of COMMAND.COM located in the C: drive root directory if it
was not previously infected by the virus.
Once the Cavaco virus is memory resident, it will infect .COM and
.EXE files when they are executed. Infected programs will have a
file length increase of 1,470 bytes with the virus being located at
the end of the file. The program's date and time in the DOS disk
directory listing will not be altered. The following text strings
are visible within the viral code:
"Do you like this Screen Saver ?"
"Cavaco - A virus created by The Portuguese Government"
It is unknown that the Cavaco virus may do besides replicate.