Klaeren Virus

Virus Name: Klaeren Aliases: Hate V Status: Rare Discovered: June, 1991 Symptoms: .COM & .EXE growth; TSR; system slowdown Origin: Italy 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, NAV/N, IBMAV/N Removal Instructions: Delete infected files General Comments: 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 besides replicate.