A computer memory product readable by a computer and storing a computer program used by a central apparatus for detecting a computer virus in transmitted and received information between the central apparatus and a terminal apparatus and providing infection information concerning the detected computer virus, the computer program comprising the steps of:
- storing a communication history of the terminal apparatus;
- registering a time of find-out, which is a time when the computer virus was found out;
- specifying a time of infection of the terminal apparatus based on the stored communication history, the registered time of find-out, and a time of installation of anti-virus software on the central apparatus, in response to detection, by the anti-virus software, of the computer virus in received information;
- specifying a route of infection of the computer virus based on the stored communication history and the time of installation of the anti-virus software;
- and
- transmitting the infection information, including the specified time of infection and the specified route of infection, from the central apparatus to the terminal apparatus.