Great article on the NSA's eternalblue with some background and measures to use to protect yourself!
But to cut through the chase...
"How To Stay Safe From Eternalblue
By far the most important thing to do to prevent attacks utilizing Eternalblue is to make sure that you’ve updated any older versions of Windows to apply the security patch MS17-10.
If, for some reason, that’s not possible, other mitigations include disabling SMBv1 and not exposing any vulnerable machines to internet access.
Ensuring you have a capable EDR security solution should go without saying, but if your organization is still behind the curve on that one, remember that passive EDR solutions are already behind-the-times."
Link to original article:
https://www.sentinelone.com/blog/eternalblue-nsa-developed-exploit-just-wont-die/#