Security Plus: Sometimes it's hard to say whether a link to a website or a domain is secure or not. While the url of the site may sometimes give you clues, you can never be sure even if you have visited thousands of times the same link.
What you can do in this case is to check the site in malware databases. There are many services that are available on the web and can do so, such as the Web of Trust.
Many of these services have as a common feature that they provide you with a result. However, if you prefer more results, as they improve the chances of a proper evaluation, then you can use services such as Virustotal.
Just visit the service, and paste the url in the box. Wait for the results to appear on your screen. Although this service is quite useful, the process takes a lot of time especially if you check connections regularly.
Here's where comes an add-on for Firefox. The Security Plus is an extension of the Firefox browser that adds a new entry to the right-click menu. The entry allows you to check a link directly to the Virustotal service.
This of course is done without having to leave the site after the results appear on the same page with a small overlay on your screen.
The results show whether the website you are connected to is pure or not with all 64 services supported by Virustotal. The extension will scan all selected links.
The main advantage with the Virustotal page is that the results appear on the same page and not on a new page that opens when you start the scan.