708 Virus

Virus Name: 708 Aliases: V Status: Rare Discovery: August, 1993 Symptoms: .COM file growth; TSR; file date/time changes; .COM file corruption; system hangs Origin: Unknown Eff Length: 708 Bytes Type Code: PRsCK - Parasitic Resident COM Infector Detection Method: ViruScan, F-Prot, AVTK, IBMAV, NAV, NAVDX, PCScan, ChAV, NShld, NProt, IBMAV/N, AVTK/N, NAV/N, LProt Removal Instructions: Delete infected files General Comments: The 708 virus was submitted in August, 1993. Its origin or point of isolation is unknown. 708 is a memory resident direct action infector of .COM programs, including COMMAND.COM. The first time a program infected with the 708 virus is executed, the 708 virus will install itself memory resident as a low system memory TSR of 1,040 bytes. Interrupt 08 will be hooked by the virus in memory. Also at this time, the virus will infect the copy of COMMAND.COM located in the C: drive root directory if it was not previously infected. Once the 708 virus is memory resident, it will infect three .COM programs located in the current directory when an infected program is executed. Infected programs will have a file length increase of 708 bytes with the virus being located at the end of the file. The program's date and time in the DOS disk directory will have been updated to the current system date and time when infection occurred. The following text strings are encrypted within the 708 viral code: "Bad command or file name" "C:\COMMAND.COM C:\COMMAND .COM *.COM .." The 708 virus will occassionally corrupt the programs it attempts to infect. These corrupted programs will have the first three bytes altered, no file length increase will occur. The file's date and time in the DOS disk directory listing will not be altered. Execution of one of these corrupted programs will result in a system hang.