Iran’s powerful Revolutionary Guard military force hacked email and social-media accounts of Obama administration officials in recent weeks in attacks believed to be tied to the arrest in Tehran of an Iranian-American businessman, U.S. officials said.

The Islamic Revolutionary Guard Corps, or IRGC, has routinely conducted cyberwarfare against American government agencies for years. But the U.S. officials said there has been a surge in such attacks coinciding with the who has pushed for stronger U.S.-Iranian economic and...