Friday the 13th is traditionally a day associated with negativity; but in May, bad luck struck on Friday the 12th. That’s when networks across the world were breached with WannaCry, malware that locked up computers and held them for ransom en masse. WannaCry spread quickly across the globe, hitting specialized networks like Britain’s National Health Service (NHS), Spain’s leading telecommunications company, Telefónica, as well as a large number of computers in Russia, Ukraine, and India.
This ransomware employs EternalBlue, a vulnerability initially discovered by the U.S. National Security Agency (NSA). This method of attack infects Windows PCs, encrypts the data stored on them, and then demands victims pay hundreds of dollars for a decryption key that unlocks their affected files. This ransomware has the special ability to spread from one PC to another, which was what helped security researchers in the NHS identify it.