"LAB"-VIRUS (5-June-1990)
Entry............... "LAB" Virus
Alias............... ---
Strain.............. ---
Detected when....... 1989
         where...... Utrecht (Netherlands)
Classification...... System (Boot sector) Virus, Reset-resident
Length of virus..... 512 Bytes
------------------------Preconditions-------------------------------------
Operating System(s). Atari TOS
Version\Release..... Version TOS 1.0 AND TOS 1.2
Computer models..... All Atari ST with TOS 1.0 or blitter TOS
-------------------------Attributes------------------------------------
Easy identification. If the bootsector is infected, the string "Virus"
                     can be found at bootsector position $02. In memory,
                     the same string can be found behind screen memory.
Type of infection...: Self-Identification: No identification.
                      The virus installs itself RAM-resident behind
                      screen memory.
Infection Trigger...: Each time a new diskette is inserted, the virus 
                      will infect the new diskette.
Storage media affected: The virus infects drive A,B
Interrupts hooked...: No Interrupts used.
                      hdv_bpb changed to infect Bootsector of new Disk.
Damage..............: Permanent Damage: Overwriting Bootsectors.
                      Transient Damage: Painting screen black.
Damage Trigger......: Damage action after 10 infections. 
Particularities.....: If virus is installed and harddisk is connected,
                      sometimes harddisk access maybe impossible.
Similarities........: ---
--------------------- Agents ------------------------------------------
Countermeasures.....: Programs that calculate the checksum and change 
                      it, if it is $1234; the sector is then regarded
                      as not executable. Reboot the system with a
                      'clean' disk! (Category 1.3).
Countermeasures successful:---
Standard means......: Write-protect the disk. 
                      Write a well-known program to the boot sector;
                      'manually' change the checksum to a value other 
                      than $1234.
--------------------- Acknowledgement ---------------------------------
Location............: Virus Test Center, University Hamburg, FRG
Classification by...: Thomas Piehl  
Documentation by....: Thomas Piehl 
Information Source..: from George R. Woodside           
Date................: 5-June-1990

.