An apparatus includes a server connected between a first computer network in which a computer virus may generate and a second computer network or a computer system as an object of security protection. In the apparatus, a collection unit collects irregular data representing a possibility of generation of the computer virus that may attack the server. A decision unit decides whether the computer virus is being generated on the computer network in accordance with the irregular data. A notification unit notifies the second computer network or the computer system of generation of the computer virus when the decision unit decides that the computer virus is being generated.