Patent ID: 8156234

Claim:
A computer-implemented method of distributing components of an antivirus program, the method comprising: receiving information on a number of file fragments of a virus pattern file and information on a server computer configured to provide missing file fragments to client computers in a multicast group; receiving a multicast of a first file fragment of the virus pattern file, the first file fragment being multicast to a plurality of client computers subscribing to receive updates of an antivirus program that uses the virus pattern file and belonging to the multicast group; receiving a multicast of a second file fragment of the virus pattern file, second file fragment being multicast to the plurality of client computers belonging to the multicast group; determining if a particular file fragment for the virus pattern file has not been received using the received information on the number of file fragments of the virus pattern file; and when the particular file fragment for the virus pattern file has not been received, requesting the server computer to provide the particular file fragment and receiving a unicast of the particular file fragment from the server computer in response to the request, wherein the server computer identifies the particular file fragment from a packet payload identifying a file fragment ID of the particular file fragment.