What is a block filter ?
Node behind Tor are not targeted I guess ?
Discussion
Block filters don't help you against this attack.
A block filter is a compact representation of the addresses in a block, which helps to find out if you have sats.
However, the attack is spying on transactions that your node is broadcasting. The best way to protect here is to use a fresh tor identity for only this tx broadcast, which Wasabi does by default.
I didn’t know that it was possible to know from the outside that your node broadcasted a specific transaction as it also relays those from other peers. How can the attacker know exactly which tx is from me or my peers (and thus their peers) ? This is concerning