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Cyber Security

Block File Conversion Websites

TL;DR

Online file conversion tools can be risky. They often host malware or steal your data. This guide shows you how to block access to these websites using your router, browser settings, and/or a hosts file.

Blocking File Conversion Websites

  1. Understand the Risks
    • Many free online conversion tools are ad-supported, leading to aggressive pop-ups or redirects.
    • Some sites download malware when you upload files.
    • Your uploaded files might be stored and misused.
  2. Block at the Router Level (Recommended)

    This is the most effective method as it blocks access for all devices on your network.

    1. Access Your Router Settings: Open a web browser and type in your router’s IP address. Common addresses are 192.168.1.1 or 192.168.0.1. You’ll need your username and password (often found on the router itself).
    2. Find the Website Blocking/Parental Controls Section: The exact location varies by router manufacturer. Look for options like “Access Control”, “Website Filtering”, or “Parental Controls”.
    3. Add Websites to Blocked List: Enter the URLs of file conversion websites you want to block. Some common ones include:
      • online-convert.com
      • cloudconvert.com
      • zamzar.com
      • convertio.co
    4. Save Changes: Make sure to save your settings and reboot the router if prompted.
  3. Block in Your Browser (Less Effective)

    This only blocks access on that specific browser.

    1. Chrome:
      • Go to Chrome Settings > Privacy and security > Site settings.
      • Click ‘See more site permissions’.
      • Under ‘Blocked’, click ‘Add’.
      • Enter the website URL (e.g., online-convert.com) and save.
    2. Firefox:
      • Type about:config in the address bar and press Enter. Accept the risk warning.
      • Search for ‘network.blacklist’.
      • Double-click on ‘network.blacklist’ to add a new string value.
      • Enter the website URL (e.g., online-convert.com) and save.
  4. Use Your Computer’s Hosts File (Intermediate)

    This blocks access at the operating system level.

    1. Locate the Hosts File:
      • Windows: C:WindowsSystem32driversetchosts
      • macOS/Linux: /etc/hosts
    2. Edit the Hosts File (Requires Administrator Privileges): Open the file with a text editor like Notepad (Windows) or TextEdit (macOS).
    3. Add Blocking Entries: Add lines at the end of the file in this format:
      127.0.0.1   online-convert.com

      Repeat for each website you want to block.

    4. Save Changes: Save the hosts file. You may need to flush your DNS cache:
      • Windows: Open Command Prompt as administrator and run ipconfig /flushdns
      • macOS/Linux: Open Terminal and run sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
  5. Consider Alternatives
    • Use offline conversion software on your computer. This is generally safer.
    • If you must use an online converter, research the site thoroughly before uploading any files. Look for reviews and security reports.
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