The notorious hacking group used the Halloween tragedy that killed more than 150 people to trick South Koreans into downloading malware.

Google says it has deployed patches for zero-day vulnerabilities that a Spanish tech company may have used to develop spyware.

Security researchers linked the program to the so-called Charming Kitty Iranian hacker group known to carry out intelligence operations.

Spyware such as NSO Group-produced Pegasus is proliferating quickly and poses a threat to privacy and national security, experts said.

The campaign is just the latest example of the increasingly sophisticated world of private zero-day exploit development, researchers said.