"Zxx"@en . . "Zxx"@en . . "Zxx is a memory resident parasitic virus. It hooks INT 21h, and writes itself to the end of EXE files that are accessed. At the beginning in August, it erases the MBR of the hard drive. It contains the string ZX-X"@en . . . "Virus.DOS.Zxx.600"@en . ".COM, .EXE"@en . . . "Zxx is a memory resident parasitic virus. It hooks INT 21h, and writes itself to the end of EXE files that are accessed. At the beginning in August, it erases the MBR of the hard drive. It contains the string ZX-X"@en . . . .