If the hacker able hack the exchange, it's a matter of time that they will hack your personal wallet.
It's frightening

We already enter year 2019 but hacker still able to hack, it's really difficult for me to explain the great side about crypto
I think it was an inside job. Binance isnt a small company, they deal with millions of dollars daily on a huge infrastructure. They definitly invested a lot of money in securing their systems, breaking into such infrastructure is nothing you can do without a deep knowledge of the topology of their network.