Remember those Shadow Brokers Leaks? Well the new ransomware taking the NHS and many european companies by storm, is using the NSA's EternalBlue exploit.
If you want to learn how to exploit this yourself, check out fuzzbunch, the NSA's Metasploit. The exploit leverages vulnerabilities in the windows implementation of the SMB protocol; the protocol that is used for sharing files on windows.
You can protect yourself from this exploit by firewalling ports 139, 445 and 3389. Or of course, don't use windows or expose to the internet. However, some sources do reveal that this extreme chain has been kicked off via free wifi networks, perhaps blackbox dropboxes in cafes/bars near to the targets.
It does also appear that this attack isn't targeted, and has just found it's way to the NHS and Telephonica.
What is your personal opinion of this attack? Is it an attack arranged by big bad hooded hackers? Or is it just karma, or something that was inevitable? Do victim's ignorance excuse the attackers actions? I'd love to hear your opinions!