Typo COM Virus

Virus Name: Typo COM Aliases: Fumble, 867, Type, 712, Typo-712 V Status: Extinct Discovered: November, 1989 Symptoms: .COM growth; resident-TOM; garbled printout (see text) Origin: England Eff Length: 867 Bytes Type Code: PRtC - Parasitic Resident .COM Infector Detection Method: ViruScan, F-Prot, AVTK, NAV, Sweep, IBMAV, NAVDX, VAlert, PCScan, ChAV, NShld, LProt, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N Removal Instructions: F-Prot, or delete infected files General Comments: The Typo COM virus is similar to the Typo Boot virus in that it will garble data that is sent to the parallel port once it has activated. Unlike the Boot virus, the .COM virus infects generic .COM files. This virus was first reported by Joe Hirst of Brighton, UK, in November, 1989. The Typo COM virus only infects .COM files on even-numbered days. Known variant(s) of Typo COM are: Typo-712: Typo-712 is a 712 byte variant of the Typo COM virus. It infects all .COM files in the current directory each time an infected program is executed, adding its viral code to the end of the file. Its memory resident portion is 224 bytes in size and hooks interrupt 16. It may intermittently interfer with keyboard input. Origin: Unknown December, 1991. Typo-867B: Typo-867B is a minor variant of the original Typo COM virus. It infects all .COM files in the current directory when an infected program is executed. It also installs a 480 byte TSR which hooks interrupt 16. Infected files will have a file length increase of 867 bytes with the virus being located at the end of the infected file. Origin: Unknown May, 1992.