A brief timeline of Iranian cyberattacks on the U.S.

Investigators are probing whether Iranian hackers are behind this week's malicious cyber activity against water systems in Minnesota. If they are found to be the culprits, it would not be the first time.

Investigators are probing whether Iranian hackers are behind this week's malicious cyber activity against water systems in Minnesota. If they are found to be the culprits, it would not be the first time.