This from The Register
"Criminals behind WannaCrypt piggybacked on publicly dumped Equation Group exploits – originally stolen from the NSA before they were leaked in April – as the distribution vehicle for the WannaCrypt ransomware.
WannaCrypt initially infects endpoints via a phishing campaign or compromised RDP (remote desktop protocol). Once the ransomware gets into a network, it spreads quickly onto any unpatched Windows computers."
Also this from El Reg
"Indications are that the attack is the work of profit-motivated cybercriminals rather than a nation state-sponsored hacking crew.
Three Bitcoin wallets associated with WannaCrypt have received almost $55,000 in transfers since the beginning of the outbreak, a pitifully small sum considering the scope of damage. It is understood the decryption keys are issued manually, too, meaning it's unlikely you'll get a key from the malware's masterminds. Essentially, don't pay the ransom.
"We have confirmation that some of the 200+ WannaCrypt victims who have paid the ransom have gotten their files back. Still, not recommended," said Mikko Hypponnen, chief research officer at security firm F-Secure, in a Twitter update."
I'll believe experts * before I believe the Telegraph.
*Yes, I know I'm not supposed to.