I'm making 2 connections to a web server. The first one is not using a proxy and the second one is using a proxy.
In the web server access.log I can see my user agent reported in two different ways.
Not using proxy:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
Using Proxy:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/FB7395
The modified part is different if I use another proxy.
It only happens using http:// sites (on https:// the string is not modified). Also, if I change the ua starting string from Mozilla/5.0 to (i.e.) Mozilla 5.0 (removing the slash) the us is not being modified.
All this make me think the proxy intercepts "Mozilla/5.0" string and modifies the build, but my proxy provider said they do not alter that. But…
Any idea? Thank you!!!
Best Answer
Your proxy provider is changing your string. There's no way that they are not. It's possible that to person you spoke to about this is unaware.
The real giveaway here is that it does not happen on TLS/SSL connections. This is because your provider cannot change this data, because they can't read it in order to change it.
It's also possible that they have a bug in their system that is performing this change, and they just don't realise it.