As part of our on-going effort to make the internet a safer place for your computer to be, Information Services have started filtering out a list of 30,000+ websites which are known to host malware (spyware, adware, viruses etc) – This makes it harder for the bad guys to install unwanted software on your computer without your knowledge.
Most of the time this will happen in the background and you won’t notice it.Â If your computer tries to visit a website which is on the list of sites that we filter, you may occasionally see a message which says that the site your computer is trying to access has been blocked.Â If this happens, don’t panic, It’s a good thing!Â The system has stopped your computer from doing something dangerous!
If you want to see an example of the type of message you would receive, see this link: http://blackhole.isys.bris.ac.uk/ (NB: This link is only available within the University Of Bristol network)
We’re doing our best to ensure that the list only contains websites which are dangerous, although with a list of sites this big it’s possible that we’ll make mistakes and block things that we didn’t intend to.Â If you think we’ve blocked something by accident, the web page you see will contain instructions for getting in touch with us and we can lift the block on that site.
It’s important to note that we’re only filtering out websites which are known to install unwanted software on your computer.Â We’re not making any moral decisions about page contents, or otherwise censoring legitimate sites, and you will not get in trouble for encountering a page on the block list. (Although if you generate a lot of blocked requests we might offer to help you clean up your computer!)
Technical details for those who are interested:
We’re importing a list of known-bad domains from several reputable sources, and collating them into one list.Â This list is then being fed to the University DNS servers.Â If your computer requests a web page from a domain which is on the list, the DNS servers provide you with the IP address of aserver on the University network instead of the real IP address.Â The server on the University network then displays the message saying “we don’t think you wanted to do that!”
This is similar to how the ResNet registration network works, where whatever website you try to access, you get redirected to the ResNet registration page.