Abstract: A network bridge (14) has an associated malware scanner (16) that serves to concatenate portions of a data file from within data packets intercepted by the network bridge (14) and then scan the data file concerned before the data file is forwarded to its intended recipient by the network bridge (14). The network bridge (14) may be inserted in a network topology without requiring significant network configuration changes. The network bridge (14) may include a packet analysis unit (56) that serves to intercept only data packets having a predetermined network layer protocol or a predetermined application layer protocol.

Abstract: A source computer 2 having a copy of a computer file that it is desired to download to a plurality of target computers issues broadcast messages via a computer network linked to those target computers. The broadcast messages indicate the availability of the computer file for download and include a download qualifying parameter. The download qualifying parameter is used by receiving target computers to determine whether or not they qualify to attempt a download from the source computer in response to the received broadcast message. Only those target computers that do qualify attempt a download. The source computer monitors how many target computers make a download attempt in response to a particular broadcast message and adjusts the download qualifying parameters in subsequent broadcast messages so that the target computers progressively download the new computer file without overloading the source computer.

Abstract: A system for scanning computer files for unwanted properties, such as containing computer viruses or being spam e-mail, allocates a priority to pending scan requests based upon the identity of a computer user associated with the scan request. In the case of a normal file access request, the computer user associated with the scan request may be the file access request or in the case of an on-demand scan, then the computer user associated with a particular scan request for a computer file may be the owner or creator of that computer file. In the case of scan requests associated with e-mails, the sender or recipient computer user may be used in the allocation of a priority level for the scan request.

Abstract: A network bridge (14) has an associated malware scanner (16) that serves to concatenate portions of a data file from within data packets intercepted by the network bridge (14) and then scan the data file concerned before the data file is forwarded to its intended recipient by the network bridge (14). The network bridge (14) may be inserted in a network topology without requiring significant network configuration changes. The network bridge (14) may include a packet analysis unit (56) that serves to intercept only data packets having a predetermined network layer protocol or a predetermined application layer protocol.