OMud-512 Virus

Virus Name: OMud-512 Aliases: V Status: Rare Discovered: August, 1993 Symptoms: .COM file growth; file date/time changes; system hangs; TSR Origin: Unknown Eff Length: 512 Bytes Type Code: PRsCK - Parasitic Resident .COM Infector Detection Method: Sweep, ViruScan, AVTK, F-Prot, NAV, IBMAV, ChAV, NAVDX, VAlert, PCScan, Sweep/N, NShld, AVTK/N, Innoc, NAV/N, IBMAV/N Removal Instructions: Delete infected files General Comments: The OMud-512 virus was submitted in August, 1993. Its origin or point of isolation is unknown. OMud-512 is a memory resident infector of .COM programs, including COMMAND.COM. When the first OMud-512 infected program is executed, this virus will install itself memory resident as a low system memory TSR of approximately 512 bytes. Interrupts 10 and 21 will be hooked by OMud-512 in memory. Once the OMud-512 virus is memory resident, it will infect .COM programs when they are opened or executed. Infected programs will have a file length increase of 512 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 viral code in all OMud-512 infected programs: "OMud." Systems infected with OMud-512 will experience frequent system hangs when programs are executed, as well as possibly unexpected access to the system hard disk.