Virus Name: CPSU-2535
V Status: Rare
Discovery: February, 1993
Symptoms: .COM & .EXE growth; decrease in total system & available free
Eff Length: 2,535 Bytes
Type Code: PRtA - Parasitic Resident .COM & .EXE Infector
Detection Method: F-Prot, ViruScan, NAV, Sweep, AVTK,
IBMAV, NAVDX, VAlert, PCScan, ChAV,
NShld, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N,
Removal Instructions: Delete infected files
The CPSU-2535 virus was submitted in February, 1993, and is from the
USSR. This virus is a memory resident infector of .COM and .EXE
programs, but not COMMAND.COM.
When the first CPSU-2535 infected program is executed, the CPSU-2535
virus will install itself memory resident at the top of system
memory but below the 640K DOS boundary, moving interrupt 12's return.
Total system and available free memory, as indicated by the DOS
CHKDSK program, will have decreased by 3,088 bytes. Interrupt 21
will be hooked by CPSU-2535 in memory.
Once the CPSU-2535 virus is memory resident, it will infect .COM and
.EXE programs when they are executed. Infected programs will have a
file length increase of 2,535 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. No text strings are visible
within the viral code in infected programs.
It is unknown what CPSU-2535 does besides replicate.