There are no code changes to this version of 1768.py, my tool to analyze Cobalt Strike beacons.

What is new, is file 1768.json: this file contains statistical data for license IDs.

Over a period of one month, I collected license ID information from these sources: threatviewio and @cobaltstrikebot.

For each license ID that is found on more than one IP address / hostname, I include simple statistics: the number of unique IP addresses / hostnames and the number of unique public keys.

When analyzing malicious Cobalt Strike beacons, I often see recurring license IDs. That’s why I decided to add logic and a JSON file to my tool, with license IDs I’ve seen before. And now this has evolved to a small repository of often seen license IDs.

Here is an example with a sample we discussed on the Internet Storm Center diary:

The license ID is 1873433027 and this ID is associated with 18 unique IP addresses / hostnames, and 15 unique public keys. This is a clear indication that this license ID is used by malicious actors. License IDs that have been seen only once, could belong to red teams, that is why they are not included in file 1768.json. The more often a license ID is seen, the higher the chance it is used by malicious actors. Of course, it is not excluded that there are legitimate license IDs from red teams in this list, but I expect they will have low frequencies.

Takeaway: if your sample has a license ID that appears in 1768.json, then it has been seen before (at least twice), and you’re likely not dealing with a pentest.