| Alias: | Klaeren Virus |
| Strain: | |
| detected when: | March 1991 |
| where: | University of Tuebingen (South-West Germany) |
| Classification: | Resident File Infector |
| Length: | 972-982 Bytes (file) |
Preconditions | |
| Operating System(s): | MS-DOS |
| Version/Release: | 2.xx upward |
| Computer model(s): | IBM-PC, XT, AT and compatibles |
| Caroname: | Hate |
Attributes | |
| Easy identification: | --- |
Type of Infection: | Program Infector: virus appends itself at end of .COM and .EXE files, enlarging the filesize between 972 and 982 bytes. |
| Infection Technique: | |
| Infection Trigger: | |
| Storage Media affected: | |
| Interrupts hooked: | |
| Stealth: | |
| Tunneling/Selfprot: | |
| Oligo/Polymorphism: | |
| Encoding Method: | |
| Damage: | On trigger condition (in May, each year), transient damage is produced. Transient Damage: On trigger condition (May), virus writes several screen pages with text "Klaeren, Ha^s, Ha^s!" (^s = scharfes s, ascii 225; Ha^s=hate), and subsequently erases CMOS RAM thus making disks etc. inaccessible. Permanent Damage: beyond consequences of lost access to devices (e.g. lost data), no permanent damage has been observed. Side Effects: ??? |
| Damage Trigger: | Damage occurs when month=5 (May), each year |
| Particularities: | Virus was found in a publicly accessible PC at University of Tuebingen (South-West Germany). The "ha^s" (=hate) message adresses Professor Klaeren (University of Tuebingen). Remark: some antiviruses identify this virus as "Klaeren"; though this name is observed when the virus action is triggered, names of innocent victims should not be used. In- stead, the length-oriented name "982" is preferred as main name. |
| Similarities: | --- |
Agents | |
| Countermeasures: | |
| Standard means: | Delete infected EXE&COM files, copy uninfected versions from original write-protected disk. |
Acknowledgements | |
| Location: | Virus Test Center, University Hamburg, Germany |
| Classification by: | Klaus Brunnstein |
| Documentation by: | Klaus Brunnstein |
| Date: | 15-July-1991 |
| Information Source: | |
(c) 1996 Virus-Test-Center, University of Hamburg