LPT Off Virus

 Virus Name:  LPT Off 
 V Status:    Rare 
 Discovered:  February, 1993 
 Symptoms:    .COM file growth; file date/time changes; interfers/disables 
 Origin:      USSR 
 Eff Length:  256 Bytes 
 Type Code:   PRxCK - Parasitic Resident .COM Infector 
 Detection Method:  Sweep, AVTK, F-Prot, ViruScan, IBMAV, 
                    NAV, NAVDX, VAlert, PCScan, ChAV, 
                    Sweep/N, NShld, AVTK/N, NAV/N, NProt, IBMAV/N, Innoc, 
 Removal Instructions:  Delete infected programs 
 General Comments: 
       The LPT Off virus was submitted in February, 1993, and is from the 
       USSR.  LPT Off is a memory resident infector of .COM programs, 
       including COMMAND.COM. 
       When the first LPT Off infected program is executed, the LPT Off 
       virus will install itself memory resident in a "hole" in low, 
       allocated system memory, hooking interrupts 17 and 21.  Total system 
       and available free memory, as indicated by the DOS CHKDSK program, 
       will not be altered. 
       Once the LPT Off virus is memory resident, it will infect .COM 
       programs, other than very small .COM programs, when they are 
       executed.  Infected programs will have a file length increase of 
       256 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 can be found within the LPT Off 
       viral code: 
               "(c) 1992," 
       LPT Off interfers with printing on the system printers by disabling 
       the functionality of the 17h interrupt. 

Show viruses from discovered during that infect .

Main Page