~ 14.28 BTC x $1735.35 per BTC = $24,781 ransom paid thus far.
Add more addresses as you find them.
As compare to a massive world wide attack, the amount collected so far is not as much as it should be. I also wonder if the people after paying the ransom, were there computer back to normal or still they remain affected by virus ?
The virus made the files encrypted and then it will decrypted once you pay $300 as a ransom. To help reducing further spreading of the ransomware possible measurement should be taken to avoid opening unknown emails and especially the one related to invoice.