The major digital asset exchanges like Binance, Coinbase, or Kraken, aren't going to institute blanket bans on Russian crypto accounts despite Ukraine's plea to freeze any and all transactions. Such a move would fly in the face of crypto's libertarian virtue, they argue, yet add that if they are forced to comply with government mandates they might have to go along.
https://www.notebookcheck.net/Most-crypto-exchanges-reluctant-to-freeze-Russian-accounts-say-that-goes-against-the-whole-idea-behind-crypto.605256.0.html
Banks offering accounts to foreigners also won't be freezing them unless their government makes them (whether it's a blanket freeze or just select entities). It would be potentially illegal. You can't just freeze assets of your customers as you please. There are contracts and laws.