A URL is essentially an easy way to remember an IP address since it consists of memorable phrases instead of a string of numbers. For this reason, every URL you encounter on the Internet is an IP address put into an easily digestible form. However, IP addresses work well beyond URLs and concern everything in your network, like your computers and peripherals.


It’s essential to understand what IP addresses are to protect yourself when using Proxy Auto-Config or PAC files, which carries risks that can cause malicious redirects. Here’s what you need to know about PAC files:


All About PAC Files

PAC files store the configuration of the proxies your organisation uses, containing prebuilt values such as URL and port number. When you use your browser, it processes the configuration then configures itself accordingly. PAC files facilitate proxy configuration, which means that each time you update your browser or add a new one to your computer, you don’t have to configure the proxy again each time. If your PAC files are located under Control Panel then Internet Options, that means it will configure itself automatically and function as intended.


The Risks of PAC Files

PAC files help redirect your browser to a proxy URL. Unfortunately, this carries the risk of malicious redirection to compromise users and steal their information. What happens is that you may have downloaded malware that creates or alters your PAC files, sending you to malware-filled or phishing websites instead of legitimate ones. You’ll need robust protection against phishing and other malware that has compromised your network.

These phishing sites gather different information, such as bank account details, secondary authentication, credit card data, and personal information like name and address. With these details, hackers can empty bank accounts, use other people’s credit cards, and use your identity to apply for loans, which you’ll have to pay since it is under your name. This scenario is called online identity theft.

Detecting Compromised PAC Files

To check if your PAC file was compromised, open Internet Options, then click on the Connection tab. Go to LAN settings and look for “Use Automatic Configuration Script.” If it is checked and you have never installed anything related to it, it’s a good sign that you are compromised. To clean your computer, check the path of the file identified here, go to the folder, and put the .pac file in the trash bin. Uncheck the option in LAN settings and empty your bin right away.


However, it’s best to reach out to threat intelligence companies with PAC file analysis and takedown services for a more comprehensive solution. FraudWatch International Security analysts can identify and analyse malicious PAC files in your network and assess their effects on your business. We can also take them down, clean them up, and reinforce your cybersecurity to protect you from further attacks.


PAC files make it easier to configure proxies, although cybercriminals exploit this to host fake DNS information for infected computers to reference, putting its users at risk. By understanding the nature of PAC files and getting in touch with cybersecurity analysts, you can protect yourself and your business from harmful attacks.


FraudWatch International is among the top threat intelligence companies offering brand protection, protection against phishing, ransomware prevention services, and many more. We protect your business from malware attacks that threaten you and your customers. Contact us today to learn more about our threat intelligence products!