Xora Virus

Virus Name: Xora Aliases: V Status: New Discovery: July, 1995 Symptoms: .EXE file growth; file date/time seconds = "24"; decrease in available free memory Origin: Unknown Eff Length: 1,028 - 1,040 Bytes Type Code: PRhE - Parasitic Resident .EXE Infector Detection Method: F-Prot, AVTK, VAlert, ViruScan, Sweep, NAVDX, NAV, IBMAV, PCScan, ChAV, NAV/N, NShld, Sweep/N, IBMAV/N, NProt, AVTK/N, Innoc 4.0+ Removal Instructions: Delete infected files General Comments: The Xora virus was received in July, 1995. Its origin or point of isolation is unknown. Xora is a memory resident infector of .EXE files. When the first Xora infected program is executed, this virus will become memory resident at the top of system memory but below the 640K DOS boundary, not moving interrupt 12's return. Available system memory will have decreased by 912 bytes. Interrupt 21 will be hooked by the virus in memory. Once the Xora virus is memory resident, it will infect .EXE files, other than very small ones, when they are executed. Infected files will have a file length increase of 1,028 to 1,040 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 appear to be altered, though the seconds field will have been set to "24". The following text string is visible within the viral code in all infected files: "xor "a" " It is unknown what the Xora virus does besides replicate.