Have you reported this to authorities? I'm not familiar with any specifics, but hopefully there is somebody out there - either law enforcement or white hat hackers - who is compiling and maintaining a list of addresses like this to be monitored on an ongoing basis. I'd suggest looking into that.
I have not as I was not the victim of the crime. I suggested that the small business report it to authorities, but I doubt local law enforcement will be able to do much about it. They may pass it along to the fed, but a $600 crime will probably not land high on their radar.
I will check to see if anyone is compiling a list of transactions involved in ransomware crime.
Thanks