System and method of selectively scanning a file on a computing device for malware

A software system for selectively scanning a file stored on a computing device for malware, the software system comprising:

• (a) a validation application operative to perform an integrity check on a file that identifies whether data in the file originated from a trusted source;
• (b) an integrity table for tracking whether the data in the file originated from the trusted source;
• and
• (c) a selective scan module configured to determine whether a scan of the file is necessary to prevent potentially exposing a computing device to malware.

A computer-readable medium bearing computer-executable instructions that, when executed on a computing device that includes an operating system for managing the storage of data on the computing device, causes the computing device to:

• (a) receive a file from a trusted source;
• (b) track modifications made to the file;
• (c) perform an integrity check on the file that determines whether all of the data in the file originated from the trusted source;
• (d) if all of the data in the file originated from the trusted source, prevent the file from being scanned for malware;
• and
• (e) conversely, if some of the data in the file did not originate from the trusted source, cause the file to be scanned for malware.