Morgot Virus

Virus Name: Morgot Aliases: Morgot.823 V Status: New Discovered: January, 1996 Symptoms: .EXE file growth; file date/time changes; TSR; decrease in available free memory Origin: Unknown Eff Length: 823 - 837 Bytes Type Code: PRsE - Parasitic Resident .EXE Infector Detection Method: ChAV, AVTK, IBMAV, NAV, NAVDX, ViruScan 2.54+, Innoc, AVTK/N, IBMAV/N, NAV/N, NShld 2.33+ Removal Instructions: Delete infected files General Comments: The Morgot or Morgot.823 virus was received in January, 1996, along with three variants. Their origin or point of isolation is unknown. Morgot is a memory resident infector of .EXE files. When the first Morgot infected program is executed, this virus will install itself memory resident as a low system memory TSR of 1,136 bytes. Interrupts 21 and 24 will be hooked by the virus in memory. Once the Morgot virus is memory resident, it will infect .EXE files when they are executed. Infected files will have a file length increase of 823 to 837 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 have been updated to the current system date and time when infection occurred. The following text string is visible within the viral code: "MORGOT" Some .EXE files will fail to function properly once Morgot infects the file. Known variant(s) of Morgot are: Morgot.841: Also received in January, 1996, this is an 841 byte fast infector version of the Morgot virus described above. It becomes memory resident at the top of system memory but below the 640K DOS boundary, not moving interrupt 12's return. Available free memory, as indicated by the DOS CHKDSK program from DOS 5.0, will have decreased by 2,960 bytes. Interrupts 21 and 24 will be hooked by the virus in memory. Once this variant is memory resident, it will infect .EXE files when they are executed or opened, but not when copied. Infected files will have a file length increase of 841 to 855 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. The following text string is visible within the viral code: "-=MORGOT 2=-" Origin: Unknown January, 1996. Morgot.948: Also received in January, 1996, this is a 948 byte variant of the Morgot virus described above. It becomes memory resident at the top of system memory but below the 640K DOS boundary, not moving interrupt 12's return. Available free memory, as indicated by the DOS CHKDSK program from DOS 5.0, will have decreased by 3,072 bytes. Interrupts 21 and 24 will be hooked by the virus in memory. Once this variant is memory resident, it will infect .EXE files when they are executed. Infected files will have a file length increase of 948 to 962 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. The following text string is visible within the viral code: "-=MORGOT 3=-" System hangs frequently occur when programs are executed. Origin: Unknown January, 1996. Morgot.1017: Also received in January, 1996, this is a 1,017 byte variant of the Morgot virus described above. It becomes memory resident at the top of system memory but below the 640K DOS boundary, not moving interrupt 12's return. Available free memory, as indicated by the DOS CHKDSK program from DOS 5.0, will have decreased by 3,152 bytes. Interrupts 21 and 24 will be hooked by the virus in memory. Once this variant is memory resident, it will infect .EXE files when they are executed. Infected files will have a file length increase of 1,017 to 1,031 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. The following text string is visible within the viral code: "-=MORGOT 4=-" Origin: Unknown January, 1996.