Hackers can hack anything that is computer generated, such as crypto. Hackers are expert on doing this. So to protect your bitcoins from hackers, it is very important to always update the btc wallet and make sure to have a secured password or change your password twice or thrice a year.
We need to hold our horses right here, Hackers can get a hold of your private keys, your passwords and bank accounts but I don't think they can hack directly the crypto currency, they can just hack a wallet of either a user or an exchange. Without some great technologies like the quantum computer, I don't think they can do it. Secured Password will not cut it, you need a lot of other ways to make your BTC wallet safe from them.