It was discovered only because of a simple human error. The hacker sending the email dispatched it to the wrong address. When the server in the premier’s office returned it with a note saying the email address had not been found, the transmission aroused suspicion that something in the original message was fishy, the authors of Check Point’s report wrote. That prompted the investigation that revealed the attempted attack — and its novel weapon.

Source: New York Times May 07, 2020 09:25 UTC