Patent ID: 7266843

Claim:
A computer program product embodied on a tangible computer-readable medium for controlling a computer to scan computer files for malware, said computer program product comprising: malware scanning code operable to malware scan all computer files stored within a storage location as addressed by an operating system to identify any computer files stored within said storage location that contain malware; identification code operable if no computer files containing malware are found in said storage location, to identify said storage location as a clean storage location; and when subsequently reading a computer file, determination code operable to determine whether or not said computer file is stored within a clean storage location and: if said computer file is stored within a clean storage location, then permitting reading of said computer file without further malware scanning; and if said computer file is not stored within a clean storage location, then malware scanning said computer file; wherein said malware scanning of all computer files stored within a storage location is performed as a background task that occurs as a function of when an associated computer system is idle; wherein said malware scanning of all computer files stored within a storage location as a background task is performed with more thorough scanning options selected than for on-access scanning applied to computer files not stored within clean storage locations and being accessed by a user; wherein said malware scanning code uses malware definition data to identify malware and, upon updating of said malware definition data to give updated malware definition data, said storage location is no longer identified as a clean storage area until it has been malware scanned using said updated malware definition data and no computer files containing malware are found in said storage location.