Custom Threat Signature for unique EXE files

tboire — Tue, 05 Jul 2016 16:43:22 GMT

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 PE file.

The sample signature was created on PAN OS Version 7.0.x :

SHA256: 92914013abfd071b0513d366bcaead978dce2f552c9d2853f4ce775604fb841f

Fill out the appropriate field under the configuration tab

Choose the standard option from the radio button and click on add to create a signature

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.

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.

topic Custom Threat Signature for unique EXE files in Custom Signatures

Custom Threat Signature for unique EXE files