I really wouldn't read too far into random aircraft suddenly appearing over Russia, FlightRadar24 themselves today had an issue with false ADS-B data being fed/injected to their servers causing most of the aircraft over Moscow to appear to be squawking 7700, my phone was pinging none stop for about half an hour with the alerts, they've since tweeted to acknowledge it. Plenty of people using false flight tracks/ADS-B data as a tool to spread false/disinformation or cause panic to the unknowing. Could be "script kiddies" as they're known messing around or people with more sinister intent, either way, pay no attention too it.