Binance said Friday that a security incident impacted about $6.3 billion in client assets, with around $3 billion frozen on-chain, marking the largest crypto hack on record.

The company later added it began recovering assets impacted by the breach after pledging to cover losses using its Secure Asset Fund for Users, which the company created in 2018 as a protection for clients in the event of a hack.

It wasn’t clear how the attack took place. The world’s largest crypto exchange initially said the hack may involve “a compromised DevOps engineer’s laptop, which allowed an attacker to gain access to a service container and submit unauthorized withdrawal transactions.” However, Co-CEO Richard Teng later said the attack involved a more…