About dparris

DISCLAIMER:   As with all custom signatures on this forum, this signature is being provided by the author as a result of enthusiasm for the product and to share ideas with the Palo Alto Networks security community.       It is:   - Not recommended for deployment in a production network of any kind without internal testing. - Not a solution to any vulnerability. - Not an official supported Palo Alto Networks signature    This write up is to help the Palo Alto Networks community with detecting a specific PDF file.    The sample signature was created on PAN OS Version 8.1.x :    SHA256: cbdf842fba661b85090e7e31fe9ed6b069a01fd82d5bd563a462185b53ab38e3   Go to custom signatures under objects, select custom vulnerability signature. Click add Fill out the appropriate field under the configuration tab     Open the Signature Tab Select add at the bottom left   Since we only have one condition it doesn’t matter if we choose the ‘and’/’or’ condition     To determine a unique string the *NIX utility xxd was used in this case, however any hex editor will work for this purpose.  The string was then converted to hex and used in a pattern match to detect the file. In this case the author of the file put what we believe to be their name in the file and that was used as a unique identifier.    5220 3120 2038 2030 5d52 432f 6e6f 6574 Once this custom signature is applied and a web browser is used to attempt to download the file the firewall will either block or alert on detection depending on the action you set.   **Warning** any custom signature should be fully tested to see if it works correctly, and for false positives. ... View more