I dont know if this is the right place for this post.
For about 2 years ago we bought 2 web gateway 7 in our organization for scanning web pages. They where set up a McAfee technician and it looked fine. But over time, they started blocking many web pages witch was safe. So I tried to test the pages with http://www.siteadvisor.com/ and it did'nt find any danger. It will eventually become a major problem because our whitelist to be miles long and the websides might be unsafe later on, but automatically approved due to our whitelist.
So my question is, you can see more specifically what the web gateway find unsafe and should url filter not be the same at the Web gateway and http://www.siteadvisor.com?
Webgateway Anti-Malware Versions:
Last Update: 100 minutes ago
Gateway Engine: 7001.1202.1796
Gateway DAT's: 1563
Can you give an example URL and the results you see using Web Gateway and Site Advisor?
In general, you should see the same results Though, the configuration of Web Gateway (e.g. if local database and/or cloud is used; usage of DNS in cases that the URL is uncategorized) or some delay when the database is updated could sometimes lead to slightly different results.
I just checked both URLs and both show up as Green/Minimal Risk but have no categories assigned.
In this case MWG applies a heuristic (enabled by default) which will do a DNS lookup and will categorize the returned IP address. If the site is hosted on a suspicious web server (because other suspicious sites are also hosted on that server) the final reputation result will also be suspicious/medium risk/yellow. This is what happens in your case.
E.g. Resolving frismus.nu I get 126.96.36.199. Categorizing then this IP through Site Advisor or trustedsource.org I get a yellow result.
If this heuristic shows to many false positives you can disable it: Go to Policy -> Settings -> URL Filter and disable the checkbox (called something like) "Do forward DNS lookup".
This is a timely thread as I'd encountered several of these head scratchers myself of late.
As Felix said, if the URL is uncategorized, the reputation of the IP is used for categorization it seems. In my case, I was seeing things getting categorized as Malicious Sites in my log files, but checking at https://www.trustedsource.org/en/feedback/url it showed the URL in my logs as uncategorized. Sure enough that same URL entered as its corresponding IP address, however, showed the same categorization I saw in my logs.