Virus Name: Klaeren
V Status: Rare
Discovered: June, 1991
Symptoms: .COM & .EXE growth; TSR; system slowdown
Eff Length: 978 Bytes
Type Code: PRA - Parasitic Resident .COM & .EXE Infector
Detection Method: F-Prot, ViruScan, Sweep, AVTK, NAV, IBMAV,
NAVDX, VAlert, PCScan, ChAV,
NShld, LProt, Sweep/N, Innoc, NProt, AVTK/N,
Removal Instructions: Delete infected files
The Klaeren virus was submitted in June, 1991, by the PCVRF. It is
reported to be from Italy. Klaeren is a memory resident infector
of .COM and .EXE programs. It does not infect COMMAND.COM.
When the first Klaeren infected program is executed, Klaeren will
install itself memory resident as a low system memory TSR of 1,312
bytes. Interrupt 21 will be hooked by the virus.
After Klaeren is memory resident, it will infect .COM and .EXE
programs over approximately 1K in length when they are executed.
Infected programs will increase in length by 978 to 996 bytes with
the virus being located at the end of the infected programs. There
will be no change in the file date and time in the disk directory.
Systems infected with Klaeren will respond sluggishly due to a
slight system slowdown when the virus is memory resident.
Klaeren is a fully encrypted virus. It is unknown what it does