Heads up, A new Ransomware doing the rounds called Petya / Petrwrap Ransomware. It targets Windows machines, make sure you have auto updates on or manually patch you windows version here. Make sure your antivirus software is up to date too.
If you want to learn more about the Petya / Petrwrap Ransomware and see how it works
watch this video here by Colin Hardy
More info on the wordfence blog here too