There is a new ransomware named Stop that also implants an information stealing trojan on computers it infects. Below is the MDB signature for both malwares.

Copy each signature to the same Notepad file (or add it to an existing MDB signature file) and save it in the ClamWin db program data folder. When you save the file, make sure it is not saved with a .txt or .text on the end. Just save it as Sigfile.mdb (select type All Files to prevent the .txt or .text at the end of the filename), otherwise ClamWin will not recognize it as a signature. The MDB signatures are for important parts of a malware and will last until the next version of the malware comes out--usually in a week or less, but some malware authors reuse the same part again, so this signature might last longer--at most for a month.

5120:cac55c427defaffc85c1a164a6baac6b:Win.Trojan.Spy-031119.1057
306688:0b071860f10f9b8703b3987a38a0e8ed:Win.Trojan.Ransom-031119.1054

Regards,