It may rezbel, this can be answered by hackers and security professionals , but i will tell you what i know,
Some hackers will build their code in side a website so that, when ever we a open a website they can hack our system, most of these attacks are related to phislers where they will try to hack your personal information, the keywords that you type and all that, there are many other things that we dont know about hacking, so if you want to be protected and dont want to worry as u r presently worrying, use a goo anti virus, beacause anti virus can block hackers and viruses that they send.