Below are some mdb signatures for recon malware that was deployed on US government agencies for months. I don’t think any agencies use ClamWin, but who knows, and it could be deployed on regular computers if "commercial" malware writers get it.

Copy mdb signatures to a new Notepad or similar text writer file and save it in the ClamWin database folder as a file named Sigfile.mdb, with a file type of “All Files”. Do not save the file as a text file. The file name should be Sigfile.mdb and nothing else.

For multiple signatures, put each signature on a separate line in a Notepad or similar file. Put mdb and hdb signatures in separate files. You can add multiple signatures to the top of an existing mdb or hdb signature file. Copy the signatures, add one blank line to the top of the file and paste the signatures there—any additional lines needed will be added. Do not add signatures to the bottom of existing signature files or you will get a ClamWin scanning error. Delete any blank lines between signatures in a file before saving the file.

After you save a signature file in the ClamWin database folder, scan one file with ClamWin to make sure it works. If you get a scan error, accept my apology, and delete the signature file from the database folder or delete only those signatures that you just posted to an existing mdb or hdb file and re-save it after first removing any blank lines in the signature file. For multiple signature files, do a scan after you save each file to help you locate a file that could cause a scan error.

After 4 weeks, the malware will probably be updated, so you can delete mdb and hdb signatures then. The date (USA) and time (24 hr) are the last two items in each signature. Yara signatures can be kept permanently if they are not for a specific malware.

Thanks to Sophos!

MDB Signatures
19456:0c21c7c418347d9cfa46a44e47c82d08:Win.Trojan.Mimikatz-041622.1052
3584:23b6119a89740dd5b6af155f91394968:Win.Trojan.Mimikatz-041622.1052
4096:d41d8cd98f00b204e9800998ecf8427e:Win.Trojan.NLBrute-041622.1054
12288:d41d8cd98f00b204e9800998ecf8427e:Win.Trojan.NLBrute-041622.1057
18784256:d41d8cd98f00b204e9800998ecf8427e:Win.Trojan.NLBrute-041622.1058

Regards,