Virus Name: 01-07 Virus Type: Memory Resident, File Infector Virus (infects .COM files). Virus Length: 639 Bytes (COM) PC Vectors Hooked: INT 21h Infecting Procedure:
1) The virus checks whether the system date is between the 1st and the 6th of January. If it is, the message:" Happy New Year " appears on the screen and the system halts. If it isn't, the virus checks to see whether it is already loaded resident in memory. If it isn't loaded, it then loads itself into resident memory by hooking INT 21h.
2) It then executes the original file.
3) After loading itself into resident memory, it will infect any uninfected file that is executed. It doesn't infect .EXE files. Damage: The system halts when the system date is between the 1st and 6th of January. Detection Method: Infected files increase by 639 Bytes. Note: The 01-07 virus doesn't hook INT 24h when infecting files. An error message occurs if there is an I/O error (such as write protect).