Staying safe on the Web

If you’re accessing the Web via Fermilab’s network, your browser will alert you if you are navigating to a dangerous site. Image: Reidar Hahn, Fermilab

The Internet these days is a dangerous place, especially when you’re surfing the Web, where a single click on the wrong link can infect your computer with viruses or malicious spyware or adware. You should always be wary when you’re on the Web.

The Fermilab computer security team operates services that provide some protection. First, each time you attempt to access the Web using the Fermilab network, the request goes through a Web proxy server. The proxy server looks at the website you are trying to visit and compares it with a constantly updated list of dangerous websites. If the site you are visiting is not on the list, the Web content is sent to your browser automatically. However, if the site is on the list, one of several actions to prevent infection takes place.

For the most dangerous or forbidden sites, your browser will display a message that access to that website is blocked. If there is a business case that requires you to visit the site, you can submit a service desk request to remove the site from the list, but, to protect the network, it is unlikely to be fulfilled.

For other sites, your browser will display a warning explaining why it is a bad idea for you to visit the site in question. In these cases you can click past the warning, but you should be aware that such actions are logged and that taking them is risky.

Even sites that you visit regularly can begin to appear on the list of dangerous sites as content, links, advertisements and other aspects of the site change. Attackers frequently plant malicious content on the most widely visited sites to propagate infections.

We recently began scanning content even from websites not on the “dangerous” list. Since we began doing this earlier this summer, we have prevented the download of hundreds of viruses that previously would have triggered alerts from desktop virus scanning and required assistance from the desktop support team.

What does this mean for you? First, heed our warnings, and use extreme caution when you click through to a dangerous site. In most cases, doing so will result in infection that could require your computer to be cleared of all content and the operating system to be reinstalled. Second, remember that when you are away from the Fermilab network, you will not be getting the benefit of these warnings and protections and your device can easily be infected. If using a mobile device, you could then carry this infection into the laboratory.

Irwin Gaines