Detection of steganography on the perimeter

A computer system, comprising:

• one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage media, and program instructions stored on at least one of the one or more computer-readable tangible storage media for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, wherein the computer system is capable of performing a method comprising:
• receiving a multimedia file;
• generating a bit level hash of the multimedia file;
• generating a perceptual hash of the multimedia file;
• comparing the bit level hash of the multimedia file to an original bit level hash of an original multimedia file, wherein the original bit level hash was created when a profile was created for the original multimedia file;
• determining that the bit level hash comparison does not match;
• comparing the perceptual hash of the multimedia file to an original perceptual hash of the original multimedia file, wherein the original perceptual hash was created when the profile was created for the original multimedia file;
• determining that the perceptual hash comparison matches;
• flagging the multimedia file based on the mismatch of the bit level hash comparison and the match of the perceptual hash comparison;
• and
• determining that the multimedia file has been modified;
• and
• triggering an investigation.

A computer program product, comprising:

• one or more computer-readable tangible storage media and program instructions stored on at least one of the one or more computer-readable tangible storage media, the program instructions executable by a processor to cause the processor to perform a method comprising:
• receiving a multimedia file;
• generating a bit level hash of the multimedia file;
• generating a perceptual hash of the multimedia file;
• comparing the bit level hash of the multimedia file to an original bit level hash of an original multimedia file, wherein the original bit level hash was created when a profile was created for the original multimedia file;
• determining that the bit level hash comparison does not match;
• comparing the perceptual hash of the multimedia file to an original perceptual hash of the original multimedia file, wherein the original perceptual hash was created when the profile was created for the original multimedia file;
• determining that the perceptual hash comparison matches;
• flagging the multimedia file based on the mismatch of the bit level hash comparison and the match of the perceptual hash comparison;
• and
• determining that the multimedia file has been modified;
• and
• triggering an investigation.