"The majority of things that happen when you load a website in your browser of choice happen in the background. Unless you have installed security extensions in the browser or software on the system, you may be completely unaware of the connections that are initiated when a page is loaded in the browser.Source: gHacks Tech News
"While you can check that manually using the browser's developer tools (hit F12 and switch to network for that), it is only displaying information to you while the page is loading.
"The Firefox web browser is probably the browser with the best selection of extensions that provide you with security information, often before you connect to a website.
"This guide provides you with a list of extensions that you may want to consider for that. ..."
Turn Firefox into a Security Information Powerhouse