I don't think it is a good idea to throw baseless rumors like this around. It could be anybody. If there isn't any proof, why would anybody think it is Russia? It is so stupid 20 years ago every terror act was done by Al-Qaeda and now Russia is the new Al-Qaeda.
Some casino gotten hacked? Russia did it.
Some bomb blew up somewhere? Russia did it.
Some guy died of heart attack somewhere? Must be a Russian spy.
Who stole my sweetroll? Fckin Russia.
I did not read in their article that there's a rumor that hackers are of Russian origin, you should post your source, not because Russia is invading Ukraine and they looked like a villain in the world we will accuse Russians of crimes like this without backing it until it is confirmed we should take out that rumor thing.
Anyway, the authorities are now investigating we will soon hear who really did this, I hope you update us more on this.