Microsoft said hackers linked to the Iranian government targeted a U.S. presidential campaign, but were not successful.

The company said in a blogpost Friday that the hackers attempted to penetrate 241 accounts, including a U.S. presidential campaign, current and former U.S. government officials, media targets and prominent expatriate Iranians.

It said the hackers were successfully able to access four accounts, but Microsoft said none of those accounts belonged to a campaign or any current or former government officials.

Microsoft did not identify the election campaign whose network was targeted by the hackers.