Abstract: A product update is used to add a licensing control mechanism to an installed computer program. The computer program is preferably a malware scanner or other program which requires regular product updating in order to remain effective in its normal functionality.

Abstract: The installation of a computer program, such as a malware scanner, may be checked to determine whether or not it has not been tampered with using an installation checking computer program to gather characteristics of the installation of the target computer program after the installation checking computer program has first been validated by a separate further computer. The installation characteristics may include operating system registry entries, installed files list, file sizes and file checksums.

Abstract: Malware definition data for mobile computing devices 2 is generated from master malware definition data 44 by selecting those classes of malware threat to which the mobile computing device is vulnerable and then selecting the matching malware items from within the master malware definition data. A PC 6 to which the mobile computing device may be connected is responsible for downloading an updated version of the master malware definition data for its own use and generates appropriate mobile computing device malware definition data for transfer to the mobile computing device when it is connected to the PC. The scanner programs of both the PC and the mobile computing device may be similarly updated.

Abstract: Archive copies of active computer files are generated and stored when a computer file is created or copied onto a computer system. These archive copies are compared with the current active copies upon subsequent access to detect malicious alterations in the active copies. If such alterations are detected, then a repair of the active copy may be made by replacing it with the archived copy. This replacement may be subject to user confirmation or user defined rules. The technique may be selectively applied to certain file types, such as executable files or dynamic link libraries, that are known to infrequently change during normal use.

Abstract: A library of anti computer virus test drivers is provided with classifications for the drivers which may be used to select the applied drivers in dependence upon which anti computer virus program is using that library. The library is typically shared between a suite of anti computer virus programs. The drivers are also classified with information that allows them to be placed in a priority order for application when scanning. In this way, the drivers that protect against the most threatening viruses may be checked for first and accordingly the highest level of protection achieved if the scanning process is early terminated.

Abstract: A library of anti computer virus test drivers is provided with classifications for the drivers which may be used to select the applied drivers in dependence upon which anti computer virus program is using that library. The library is typically shared between a suite of anti computer virus programs. The drivers are also classified with information that allows them to be placed in a priority order for application when scanning. In this way, the drivers that protect against the most threatening viruses may be checked for first and accordingly the highest level of protection achieved if the scanning process is early terminated.

Abstract: A computer file update triggering technique uses tags embedded within e-mail messages sent to connected computers to indicate the existence of an updated version of a computer file to those connected computers. The connected computers may then automatically download the updated version of the computer file. The notification via e-mail of the existence of the updated computer files may be provided as a subscription service by the computer file provider.