Kremlin: Russia is preparing to be disconnected from SWIFT (opens in new tab)

The receiving instutition(s) could safely assume that the message is actually from Bangladesh Bank and whoever was sending them has the authority to act on their behalf even if it was not true. If Bangladesh Bank allowed hackers to send messages in their name, they are still fully responsible for their content, the recipient does not have necessarily to verify anything (for a counterexample, consider the legal risks involved with not verifying who has the authority to sign for a large international contract) unless a specific bilateral contract specifies that - like in the Bangladesh 80M case, there's no blame or risk placed on the message recipient/executor (Federal Reserve Bank of New York), they had the rights to assume that the orders were from Bangladesh bank, and all the losses from that case were solely on the Bangladesh bank. In all the major cases there have been lawsuits or threats of them - because why not try - but the general precedent is that those lawsuits fail and the recipient is reasonably safe to make that assumption.

In a similar manner, if the SWIFT infrastructure itself was hacked and fraudulent messages inserted (this has not ever happened AFAIK), you still can assume that the messages are valid, and that in that case the liability (insured!) for any losses would be on SWIFT.

The real issue is the cooperation of banks centered around the dollar system, and the US as the world's custodian and monopoly issuer of dollars, is going to dominate any such system, regardless of which protocol is chosen for communication, or where the headquarters are located of whatever technology company has been selected to create the protocol. It is not a SWIFT system, it is a dollar-system. When you obtain dollars by selling goods to the U.S., you may think you have those dollars, but they are held in custodial accounts in U.S. banks, and subject to US law, regardless of whether you believe they are "your" money. This makes you subject to US law. You can't really withdraw dollars from the United States (or from any country in a fiat system). We don't live in a world of specie flows, we live in a world of custodial accounts.

That statement causes a lot of consternation, particularly in the eurozone, which is desperately trying to position the euro as a rival to the dollar, but as the Eurozone has discovered, what matters is not the nationality of the account holder, but the nationality of the custodial bank. It's impossible for any system which is a net exporter to become a big player in the international system. But everyone holds dollar claims - everyone has custodial accounts in US banks, and so the US can even disrupt transfers that only happen within the EU, because so much international trade is conducted with dollars, even trade between two EMU member nations, and this is an endless source of agitation for those claiming that SWIFT is independent of the US. It's not. Russia realizes that, and for a long time has been complaining about being forced into the global dollar system in order to conduct trade. It means the US can seize whatever Russian funds are used for international purchases and Russia can't do anything about it. And the US has not been shy at using it's control over the international currency markets to seize funds from nations it doesn't like, such as Iran, or lock out/or seize funds from others.

So there are a lot of reasons for Russia to want to separate itself from this system that have nothing to do with the specific type of legal structure used by the main subcontractor for this international dollar system. For Russia, it's all about trying to gain autonomy from the US -- Belgium or the EMU is not a factor.