How did hackers steal ₹848 crore in Bitcoin from offline wallets?

Hackers stole nearly 1,367 Bitcoins worth about $89 million (₹848 crore) from 4,585 offline crypto wallets by exploiting a flaw in Coldcard hardware wallets. Instead of using secure hardware random number generator, the wallets relied on a weaker software method. This made their security keys predictable allowing hackers to recreate private keys.