With the recent ransom attacks going on please ensure you anti-virus and malware scanner are up-to-date.
Below is some information from Microsoft to help protect you against these attacks. There is a free scanner as well you can download and run. This free scanner expires after 10 days, please download it again to receive updated protection.
Malware Detection Windows Defender, System Center Endpoint Protection, and Forefront Endpoint Protection detect this threat family as Ransom:Win32/WannaCrypt.
Useful information - https://docs.microsoft.com/en-us/msrc/customer-guidance-for-wannacrypt-attacks
Update 28/06/2017 - In light of the latest attacks called "Petya Ransonware" ensure your anti-virus is up-to-date. Windows Defender should be the following
Malware Detection Ensure you have a definition version equal to or later than: • Threat definition version: 188.8.131.52 • Version created on: 12:04:25 PM : Tuesday, June 27 2017 • Last Update: 12:04:25 PM : Tuesday, June 27 2017