Hacking techniques and methods are constantly evolving, as are the fixes for them. This means many previously common exploitation methods become obsolete as new ones appear. It can also mean that the exploits simply change, but they are still genuine and dangerous. One example of an old area of concern for many is public WiFi. The concern used to be that public WiFi was insecure and hackers could use it to steal your data, but is this still the case?
Public vs. Private WiFi
To understand how public WiFi can be dangerous, it is first important to understand the distinction between public and private WiFi. As you read this, you are likely connected to WiFi or ethernet. Ethernet is the wired internet connection used typically for desktop computers, and WiFi is the wireless connection used by laptops and phones. A WiFi network is shared between all devices connected to the same network.
Private networks are typically what you will find in your home or workplace. These are restricted networks with limited access where you can assume that nobody malicious is sitting in the network. Private networks will be password protected, and the password will not be given out freely to prevent anyone from being able to get into the network if they are close enough to the router.
Public networks are open networks that anyone can join. An example of this would be the WiFi at a coffee shop or an airport. There is no way of knowing who is connected to a public network. In general, devices connected to the same network will be able to see each other and communicate with each other. This itself is not necessarily a threat, but it can lead to dangerous situations.
Public WiFi Attacks
A common misconception is that hackers can listen in to your internet connection and see what you are doing on public networks. Almost any modern website is equipped with the latest encryption standards, meaning that data being passed around will not be visible to attackers. The threat of a hacker being able to listen in and capture sensitive logins is mostly irrelevant with modern internet safeguards.
The problem that can still come up with an unsecured network is an attacker forcing a man-in-the-middle attack. This is when a hacker sits in the network and captures all of your traffic against a legitimate website, and passes back their traffic. This will largely look the same to the end user, but in this instance, the hacker can read all network traffic in cleartext. To do this, the hacker is the one making the connection to the legitimate website with your valid data that they capture from your connection attempt.
Another threat that can come up is a hacker spreading malware through file sharing. Many machines are configured to support some sort of file-sharing protocol, such as SMB. If these are not properly configured, it may be possible for strangers to upload malicious files to your machine without you noticing. These can be dangerous malware files that let the attacker remotely access your machine and find personal data.
It may also be possible for a hacker to exploit a vulnerability in another service being hosted on a machine in public WiFi. If you have a web server running on your laptop for collaboration with your team, and this web server has a severe vulnerability that could allow a remote attacker to achieve command execution, they will be able to remotely access your file system through the vulnerability.
Staying Safe With Public WiFi
The good news is that defending against these attacks is fairly simple. Modern browsers are configured to warn users when man-in-the-middle attacks are detected with a certificate warning. Seeing one of these pop-ups should alert the user that something is wrong and they may not be connecting to the real site. Browsers will typically prevent you from accessing pages where this sort of attack is detected and guide you back to safety.
Defending against attacks against your machine’s file system typically involves best practices and proper anti-malware software. Make sure that file-sharing protocols are properly configured to restrict unauthorized access and that everything running on your machine is kept fully up to date. A good anti-malware program can detect dangerous files and attacks and alert you that something bad is happening.
The risk of using public WiFi has greatly fallen as cybersecurity standards have increased over time. This does not mean that it is completely risk-free, but the internet is now far safer than it once was. Keeping your machine fully up to date and looking for anything that seems out of the ordinary is a great best practice to protect yourself against attacks on public WiFi.
