On October 29th, more than $6 billion in digital assets vanished from Binance, the crypto exchange used by millions of people from Lagos to Seoul to São Paulo. Within days, the Federal Bureau of Investigation had a name for the culprit: North Korea. The agency says the theft was carried out by a state-linked group it calls "TraderTraitor", and that the amount stolen exceeds $6 billion. The FBI's announcement is striking for what it contains and for what it leaves out.

It says that, working with the Secret Service and IRS Criminal Investigation, it has watched the hackers convert the stolen tokens mainly into Ethereum. That is a practical step: Ethereum can be moved through decentralised finance platforms and instant-swap services, which allow funds to change form quickly and often without the identity checks that a traditional bank would demand. The agency expects the money to pass through further rounds of laundering. What it did not publish is the evidence behind its attribution, so outsiders must, for now, take the conclusion largely on trust.

Even so, the claim fits a pattern. United Nations investigators have repeatedly argued that North Korea uses cyber theft to finance its weapons programmes while under heavy international sanctions. If that is true here, a single intrusion may have raised more money than many small countries earn from a year of exports. For ordinary users, the immediate news was calmer.