Microsoft recently confirmed the existence of an exploit which currently affects almost all versions of Internet Explorer. This exploit could allow malicious websites to gain access to and infect vulnerable systems by visiting the website. Microsoft released a Security Advisory here: https://technet.microsoft.com/en-us/library/security/2963983.aspx
To stay safe, we encourage our customers to use popular free alternatives to Internet Explorer such as Google Chrome or Mozilla Firefox. Keep your software such as web browsers and virus scanners up to date with the latest patches, and be careful when visiting links from unknown sources which ask you to install plugins or supply user credentials.
You can read more about it here