I am going to sound like a broken record [again]. Ransomware is still alive and well and unfortunately that is [in part] thanks to people that do not follow basic security practices.
The latest Ransomware “a la mode” is Wanna Cry, good summary here: https://community.sophos.com/kb/en-us/126733 What is really sad and makes me want to cry (pun intended) is that it exploits a vulnerability from March 2017, aka, if you had that patch installed you would be much better protected.
In this day and age, patching is not a nice to have, it is one of the most basic step you must take to protect yourself, please read here for more: 8 Steps to stop Ransomware: https://alcit.com/8-steps-to-stop-ransomware/. If you still do not have this covered, I would suggest professional help, many firms out there specialize in keeping you up to date and out of trouble (including us).
Good write up from Microsoft: https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/
One important thing to note, Microsoft has exceptionally released a Windows XP patch on Friday, so make sure you deploy ASAP to your Windows XP system.
Here are the links to the XP Patches: