Cold storage — using physical offline devices such as hard drives, safe-deposit boxes or USB sticks — is the gold standard in crypto security. So the hackers were able to use that knowledge to brute force their way into thousands of online wallets. This isn’t the first time the physical storage of crypto keys has failed to keep wallets secure. Crypto owners surely know by now that this asset class comes with its own set of alarming security risks. France has suffered a wave of gang-coordinated attempts, accounting for 38% of all documented wrench attacks since the start of 2025, according to a database compiled by Bitcoin security expert Jameson Lopp.