The hacking attack was said to have lasted for 34 months, holding schools, hospitals, universities in several countries to ransom - earning the perpetrators millions of dollars in the process.
Now US prosecutors have charged two Iranians they believe were behind the attack - though justice is perhaps unlikely.
“Although the alleged criminal actors are in Iran and currently out of the reach of US law enforcement,” the FBI said, “they can be apprehended if they travel, and the United States is exploring other avenues of recourse.”
They are accused of carrying out a ransomware attack - malicious software that locks files and systems and demands a fee to unlock them.