Microsoft has announced there is vulnerability in Internet Explorer across all version of Windows which can be exploited by hackers to gain the same rights as the current user. This could be used to take control of the system if they have managed to gain administrative rights. Attackers could then modify data, install software and carry out other malicious activity.
Microsoft state they are aware that attacks have taken place using this method, but to date they are still working on a fix for the issue. Users are advised to consider using a more modern browser such as Microsoft Edge instead.
https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/ADV200001