"few expected Russia to arrest ransomware gang members before today"
I don't think anybody was expecting that.
When I started reading this article, my eyes went wide open.
Now that I have finished reading it though, the fact that Russian FSB agents are operating in Ukraine, a nominally indepent country, is telling. I'm sure that, normally, Russia should have asked Ukraine to take care of the arrests. It doesn't sound like there was any such diplomatic niceities. Putin just sent in his jackboots and they did the job.
As if Ukraine was part of Russia.
I'm glad those bastards got their comeuppance, but I would have been happier if it had been in a proper, legal fashion.