AntiCMOS Virus

Virus Name: AntiCMOS Aliases: AntiCMOS.A V Status: Common Discovery: 1994 Isolated: April, 1995 Symptoms: BSC; Master boot sector (partition table sector) altered; decrease in total system & available free memory; System CMOS / Setup information erased Origin: Unknown Eff Length: N/A Type Code: BRhX - Resident Boot Sector & Master Boot Sector Infector Detection Method: F-Prot, ViruScan, AVTK, IBMAV, NAV, Sweep, NAVDX, VAlert, PCScan, ChAV Removal Instructions: General Comments: The AntiCMOS virus was received in April, 1995, though it has been reported from sites in North America for several months. AntiCMOS is a memory resident infector of diskette boot sectors as well as the system hard disk master boot sector. When the system is first booted from an AntiCMOS infected diskette, this virus will infect the system hard disk master boot sector. It does not become memory resident at this time. AntiCMOS becomes memory resident when the system is booted from the system hard disk. When the AntiCMOS virus is memory resident, total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 2,048 bytes. Once the AntiCMOS virus is memory resident, it will infect un-write protected diskettes by infecting the diskette boot sector when they are accessed, though it does not always infect the diskette. The AntiCMOS virus contains code to erase the CMOS or system setup information.