Didier Stevens

Tuesday 15 June 2021

Update: 1768.py Version 0.0.7

Filed under: My Software,Update — Didier Stevens @ 0:00

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.

1768_v0_0_7.zip (https)
MD5: D93AC5707FD0B5315A1225121071C7F2
SHA256: B417790451681643B2269AC516A99F3CEE9F7F374AB529FD53D5702A70F79409

Friday 11 June 2021

Update: Python Templates Version 0.0.5

Filed under: My Software,Update — Didier Stevens @ 10:14

Here is an update to my Python templates.

I use these templates as a starting point for new tools or for quick development of ad-hoc tools.

I also recorded a video showing how to use my template to create your own tool: ssdeep Python Example Based On My Templates.

python-templates_V0_0_5.zip (https)
MD5: 137878F4D7F799436F76C0119E6BB621
SHA256: 5A68B115B5616BC35CFB4DDEA64C029BF10DDCD6BFF5E4B9D3D4DBBC0FBD6651

Tuesday 25 May 2021

Update: base64dump.py Version 0.0.14

Filed under: My Software,Update — Didier Stevens @ 0:00

This new version of base64dump.py supports a new encoding: NETBIOS Name encoding.

NETBIOS Name encoding is very similar to hexadecimal encoding: in stead of hexadecimal digits 0-9 and a-f, letters A-P are used.

I encountered this in DNS TXT records of a Cobalt Strike DNS stager. More on that later.

base64dump_V0_0_14.zip (https)
MD5: 35BF4900BED40E828887C7601F9C8751
SHA256: 2F58F630D9B12D2B70CECF35728096A247890808E44DAB9C94400A073D5E29BF

Sunday 23 May 2021

Update: re-search.py Version 0.0.17

Filed under: My Software,Update — Didier Stevens @ 0:00

This new version of re-search.py adds gzip support and filtering of private IPv4 addresses:

re-search_V0_0_17.zip (https)
MD5: 8945F435BDA03D73EF7A2BA1AA64A65E
SHA256: 0D74709B9F26FC7F6EEADAEE1BAA3AF7AADAA618F88B1C267BA5A063C8E3D997

Saturday 22 May 2021

Update: 1768.py Version 0.0.6

Filed under: My Software,Update — Didier Stevens @ 15:06

This new version of 1768.py, my tool to analyze Cobalt Stike beacons, has fixes, support for more encodings, and an option to output the config in JSON format.

1768_v0_0_6.zip (https)
MD5: EB9C949BB7B5DD3EF9ECEBF7F3C21184
SHA256: 3EC0BB7B41CC5C0E1534F09BAE67D62B220F8D83A7F02EC0F856F8741F86EB31

Monday 8 March 2021

Update: 1768.py Version 0.0.5

Filed under: My Software,Update — Didier Stevens @ 0:00

I updated the analysis logic in this new version of my tool 1768.py to analyze Cobalt Strike beacons.

There’s a new option -c (–csv) to output the config values in CSV format.

And now with option -r (–raw), identical configs are de-duplicated.

1768_v0_0_5.zip (https)
MD5: 83D7A867B93FAC13BA24F17DDA994A9A
SHA256: CBCB84B9C4D8C1ED05983C2A211E3EA6029E69782FDDD6E15181EE4F47383EB5

Sunday 7 March 2021

Update pecheck.py Version 0.7.13

Filed under: My Software,Update — Didier Stevens @ 0:00

This new version of pecheck.py, my tool to analyze PE files, outputs the hash of the embedded Authenticode signature.

pecheck-v0_7_13.zip (https)
MD5: 5B5179FFBE7530AA60C7182B830B54AB
SHA256: 4CFAF98CC8F3B06E3BBD7D6F37040B47641C38E49BD2975165FB328D50D3F08C

Saturday 6 March 2021

Update: nsrl.py Version 0.0.3

Filed under: My Software,Update — Didier Stevens @ 13:28

I use my tool nsrl.py to match a list of hashes with the Reference Data Set of the National Software Reference Library.

This is a Python 3 update and small change to support a change in RDS ZIP file structure.

nsrl_V0_0_3.zip (https)
MD5: A86E3EB076B467C64A520256556EDADA
SHA256: 8760B20A918CD135B7D79F7567C240AEF4840325BE9656D684BFD119A017E86F

Sunday 28 February 2021

Update: oledump.py Version 0.0.60

Filed under: My Software,Update — Didier Stevens @ 23:08

This new version of oledump.py brings an update to plugin plugin_biff to help with the recovery of protection passwords.

oledump_V0_0_60.zip (https)
MD5: BC7631059077294223BB225D16FB7186
SHA256: D847E499CB84B034E08BCDDC61ADDADA39B90A5FA2E1ABA0756A05039C0D8BA2

Sunday 21 February 2021

Update: re-search.py Version 0.0.16

Filed under: My Software,Update — Didier Stevens @ 12:20

This new version of re-search.py, my tool to search files with a builtin library of regular expressions, brings an update to the url and url-domain regexes to match hostnames with underscores (_) and a Python 3 fix.

re-search_V0_0_16.zip (https)
MD5: 21A7096116F50CCA051A152066B2DB50
SHA256: 4A3AC1B1BED68660316011F14EFC84B344BE3FF7E335CDFA8F1AAA2C0D2D06B0

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