Dr Shifro, a Russian-language organisation presenting itself online as a ransomware decryption agency, claims that it's "the only company that specializes in decrypting files", urging users: "Call – we will help!"
While I admit that I've not seen the full claims directly, from this quote it doesn't appear that he is making any false claims. He is not saying that he cracks the encryption, but that he decrypts the files. This is what he does: he buys the keys from the ransomware creator and decrypts the files for his client.
What he is doing is still sort of unethical (he's not very clear about what he does, and it would be understandable for the client to assume he was cracking the encryption), but he is basically acting as a consultant. The client pays him to procure the keys and decrypt their data with them, just as a person may pay someone to buy the components and build a PC for them. It's dodgy only because he's not up front about how he decrypts the data.
Biting the hand that feeds IT
