It's almost certainly simply a widely-targeted email that was "intended" to hit individuals via mass spam that happened to hit the wrong individual (who is probably having a Very Bad Day now) and took down the NHS. And my "almost certainly" is really just my inner engineer hedging; the fact that they're asking hundreds of euros worth of ransom for so much is basically proof of what I said.

Unfortunately, the state of security right now is such that these wide-band transmissions can still pick up a lot of hits.