But it remains unclear how WannaCry got onto computers in the first place. Experts said its rapid global spread suggests it did not rely on phishing, in which fake emails tempt the unwary to click on infected documents or links. Analysts at the European Union cybersecurity agency said the hackers likely scanned the internet for systems that were vulnerable to infection and exploited those computers remotely.
Once established, WannaCry encrypted computer files and displayed a message demanding $300 to $600 worth of the digital currency bitcoin to release them. Failure to pay would leave the data scrambled and likely beyond repair unless users had unaffected backup copies.
RANSOM PAYMENTS
Investigators are closely watching three bitcoin accounts associated with WannaCry, where its victims were directed to send ransom payments. The digital currency is anonymized, but it’s possible to track funds as they move from place to place until they end up with an identifiable person.
So far, there have been no withdrawals from those accounts.