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Crypto firms and law enforcement are racing to recover more than $6 billion worth of cryptocurrency stolen from Binance before hackers manage to hide the funds.

The firms say they're in a "cat and mouse game" against alleged North Korean hackers who are using a combination of crypto obfuscation techniques and professional global money laundering networks to turn their digital coins into fiat currency, according to experts who spoke to CNBC.

These moves underscore how hard it can be to recover the stolen funds after a crypto hack.

"Ultimately, they're [hackers] trying to off-ramp it [crypto] to fiat.…