Bobo Virus

Virus Name: Bobo Aliases: Bobo.530 V Status: New Discovery: October, 1994 Symptoms: .COM file growth; decrease in total system & available free memory Origin: Unknown Eff Length: 530 Bytes Type Code: PRhCK - Parasitic Resident .COM Infector Detection Method: AVTK, ViruScan, IBMAV, Sweep, F-Prot, NAV, NAVDX, VAlert, PCScan, AVTK/N, Sweep/N, NShld, IBMAV/N, NProt, NAV/N, LProt Removal Instructions: Delete infected files General Comments: The Bobo virus was received in October, 1994. Its origin or point of isolation is unknown. Bobo is a memory resident infector of .COM files, including COMMAND.COM. When the first Bobo infected program is executed, the Bobo virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, not moving interrupt 12's return. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 1,024 bytes. Interrupts 1C and 21 will be hooked by the virus in memory. Once the Bobo virus is memory resident, it will infect .COM programs, including COMMAND.COM, when they are executed. Infected programs will have a file length increase of 530 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 strings are visible within the viral code in all Bobo infected programs: "Happy Birthday, Bobo!" "BOBO"