TCP Connections To “”

I do not need a solution (just sharing information)

We have found an enormous amount of blocked traffic on our proxies that is going to tcp://

I know what the URL is used for, that is not the question.
The big question mark for me is the TCP:// connection that is being blocked. This is expected behaviour by the proxy. Question is why TCP?

The client as in the configuration is using the IE proxy config, which is a PAC-file in the end.
After testing with the URLs listed under, I can tell that one of the links is being blocked and the other works.

Is there anyone with an idea why these connections happen?



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