Any one have ideas how to signed message trough Ethereum Network? my friend used metamask address for post proof on several bounties campaign.
Being able to sign a message from an eth address that has been posted on this forum should suffice, there's no point in writing the binance's bitcoin address.
Btw, if signing an ether address is considered valid on this forum then your friend is in luck, I hardly found anyone ever using this method for account recovery.
If the OP can use Google Translate, then I can suggest reading this thread, which clearly describes how a user was able to recover an account on this forum using an ETH address. His account was also hacked, and he didn't have any messages containing a Bitcoin address, but the recovery team helped him save the account after signing from a different address.
https://bitcointalk.org/index.php?topic=5284615.0