Whether you’re at home, in the office or on a public Wi-Fi network, you never know who might be spying on your internet activity. It could be a local government agency, the police or even a hacker. These cyber criminals may steal your passwords, personal information or even your credit card data. If you use a VPN to protect your privacy, these bad actors will have to work much harder to follow in your digital footsteps.
But what do they have to go on? You might have installed a VPN identify VPN connection client or connected via a virtual private network connection to bypass your company’s firewall and access resources in the cloud. Your VPN server becomes the source of your data, making it difficult for anyone to see what websites you visit or any other online activities you engage in. This is especially true for companies that utilize virtual private networks to allow employees to work remotely from home or other locations outside of the office.
Your ISP can track your activity and see which websites you visit, but they’re not able to identify whether you’re using a VPN to hide your location or protect your privacy. This makes VPNs a popular tool for both good and bad purposes. For example, many people use VPN connections to browse the internet anonymously and avoid data collection by large corporations, but cybercriminals also abuse VPNs and proxy connections for phishing, credit card chargeback fraud, spamming and click fraud.
A VPN can be detected by software that is designed to detect and block VPNs. These programs are usually based on deep packet inspection, which involves scanning each internet connection to identify specific metadata that can indicate the presence of a VPN. These tools typically look for metadata in the connection such as an “assigned interface” or other indications that a VPN is being used.
Besides looking for metadata, VPN detection software might compare the incoming data to a list of known VPN servers’ IP addresses. If the incoming data matches one of these, the program will blacklist the user’s IP address. Some programs might also use geoIP tracking to check the location of a person’s IP address. If the IP address changes to an unusual location in an unrealistic timeframe, it might be a sign that the person is using a VPN.
Finally, VPN detection programs might also examine the connection ports that a device uses to connect to the internet. Certain file-sharing programs, like torrenting and Usenet programs, often use ports that are commonly blocked by VPNs. This can make it easier for these tools to spot VPN users, although a reputable VPN such as Private Internet Access will let you manually change the port that your connection uses so it’s less likely to be blocked by these programs. The most common port is 1194, so if your VPN is being detected, try changing the port to something else such as 443 (although this has several known vulnerabilities).