System and method for malicious code purification of portable network graphics files
An information handling system improves detection of steganography data embedded in a portable network graphics file by parsing the portable network graphics file to determine a location of a portable network graphics signature in the portable network graphics file, and determining whether there is data embedded in the portable network graphics file before the portable network graphics signature. The embedded data may then be removed from the portable network graphics file.
1. A method to improve detection of steganography data embedded in a portable network graphics file, the method comprising:
detecting, by a hardware processor, the portable network graphics file; parsing the portable network graphics file to determine whether first eight bytes of the portable network graphics file in a header of the portable network graphics file is a portable network graphics signature: in response to determining that the first eight bytes of the header of the portable network graphics file is not the portable network graphics signature, determining a location of the portable network graphics signature; and
if there is embedded data before the location of the portable network graphics signature, then removing the embedded data from the portable network graphics file; and
subsequent to the removing of the embedded data from the portable network graphics file, setting a flag to indicate that the embedded data in the portable network graphics file has been removed.
2. The method of claim 1 , further comprising outputting results to a display device.
3. The method of claim 1 , further comprising determining whether to analyze the portable network graphics file for potential steganography.
4. The method of claim 3 , wherein the determining whether to analyze the portable network graphics file for potential steganography includes determining whether at least one of a plurality of stenographic criteria is satisfied.
5. The method of claim 4 , wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been downloaded.
6. The method of claim 4 , wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been backed up.
7. The method of claim 4 , wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been replicated.
8. The method of claim 4 , wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been restored.
9. An information handling system comprising:
a plurality of processors; and
a memory having code stored thereon that, when executed by one of the processors, performs a method including:
detecting a portable network graphics file;
parsing the portable network graphics file to determine whether first eight bytes of a header of the portable network graphics file is a portable network graphics signature;
in response to determining that the first eight bytes of the header of the portable network graphics file is not the portable network graphics signature, determining a location of the portable network graphics signature;
if there is embedded data before the location of the portable network graphic signature, removing the embedded data from the portable network graphics file; and
subsequent to the removing of the embedded data from the portable network graphics file, setting a flag to indicate that the embedded data in the portable network graphics file has been removed.
10. The information handling system of claim 9 , wherein the memory having code stored thereon, when executed by one of the processors, performs the method further comprising outputting results to a display device.
11. The information handling system of claim 9 , wherein the memory having code stored thereon, when executed by one of the processors, performs the method further comprising determining whether to analyze the portable network graphics file for potential steganography.
12. The information handling system of claim 11 , wherein the memory having code stored thereon, when executed by one of the processors, performs the method wherein the determining whether to analyze the portable network graphics file for potential steganography includes determining whether at least one of a plurality of stenographic criteria is satisfied.
13. The information handling system of claim 12 , wherein the memory having code stored thereon, when executed by one of the processors, performs the method wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been downloaded.
14. The information handling system of claim 12 , wherein the memory having code stored thereon, when executed by one of the processors, performs the method wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been backed up.
15. The information handling system of claim 12 , wherein the memory having code stored thereon, when executed by one of the processors, performs the method wherein one of the stenographic criteria is satisfied when a field associated with the portable network graphics file indicates that the portable network graphics file has been modified after the portable network graphics file has been replicated.
16. A non-transitory computer-readable medium including code for performing a method, the method comprising:
detecting a portable network graphics file;
parsing the portable network graphics file to determine whether first eight bytes of a header in the portable network graphics file is a portable network graphics signature;
in response to determining that the first eight bytes in the header of the portable network graphics file is not the portable network graphics signature, determining a location of the portable network graphics signature;
if there is embedded data before the location of the portable network graphics signature, then removing the embedded data from the portable network graphics file; and
subsequent to the removing of the embedded data in the portable network graphics file before the portable network graphics signature, setting a flag to indicate that the embedded data in the portable network graphics file is removed.
17. The non-transitory computer-readable medium of claim 16 , including code for performing the method, the method further comprising determining whether to analyze the portable network graphics file for potential steganography.
18. The non-transitory computer-readable medium of claim 16 , including code for performing the method, the method further comprising setting a flag to indicate that the embedded data in the portable network graphics file has been removed.