1. A computer implemented method for identifying and characterizing stored electronic files, the method comprising: under control of one or more configured computer systems: selecting a file from a computer storage medium; generating a checksum associated with the selected file according to at least one of: generating the checksum for graphics files based on vector graphics analysis; or dividing a graphical image file into blocks and comparing relationships between the blocks; comparing the checksum associated with the selected file to one or more checksums associated with one or more of a plurality of unauthorized files; determining that the checksum associated with the selected file matches one of the plurality of checksums associated with the unauthorized files; and characterizing the file as an unauthorized file.