I think Bitcoin can not be attacked because Blockchain technology is now growing and no one knows how Bitcoin was created. Only exchanges are attacked and this really does not affect Bitcoin

There is one known attack that is possible to perform on Bitcoin. It's called a "51% attack". To perform this attack you have to have the majority of hashpower of Bitcoin network. Fortunately, this attack is too expensive and unlike to happen. Bitcoin network will be safe for a long time. Our computers are still too slow to crack encryption protocols.

In my opinion, everything online can be hacked but it would not be a piece of cake for the hackers, they would need extraordinary set of equipment, skills, method, time, etc. for the hack to commence. What we can do about this is to secure our keys and passwords, avoid clicking suspicious links, check your surroundings, have an offline wallet if you have massive amount of bitcoins, get a secure e-mail, etc. Hackers use different kinds of methods to hack, we must know how to protect ourselves from their methods.