We all use Wi-Fi, whether at home or at a coffee shop. Using public wifi has never been a good idea for tasks that you may need privacy for such as Internet Banking. Researchers have now uncovered a flaw that makes Wi-Fi vulnerable to being hacked, which has been named “Krack”. The WPA2 standard, which is a common security standard for Wi-FI, can now be exploited to read messages, banking information and intercept sensitive files using Krack. To do so, the hacker would need to be near the wireless access point to be able to connect. The hacker would only be able to intercept your data if the website you are on is not properly encrypting user data. As you can see in the above video, even if you are using a website that is HTTPS compatible and displays the lock symbol, you still are not safe.
While Krack has only been used for research purposes, it is possible for a hacker to implement this hack in a public setting. A top target for hackers would be a public Wi-Fi network since these networks are often not password protected in the first place and there are loads of users at the same time.
I suggest you avoid using public Wi-Fi for anything where you are going to be logging into a site at this moment and definitely do not do internet banking on public Wi-Fi networks. Be safe.