Even as the presidents of Iran and the U.S. speak to each other (on the phone) for the first time since 1979, it looks like Iran hasn't given up its cyberwar against the U.S. According to the The Wall Street Journal, a group of hackers either working directly for the Iranian government or with its approval accessed an unclassified Navy computer network. 

The paper calls the Navy hack "one of the most serious infiltrations" on Iran's part of U.S. networks, noting that officials don't believe the hackers stole anything significant. But, the action itself could speak volumes, demonstrating "a more potent Iranian hacking capability than previously believed," in hinting of the country's ability to access U.S. military systems. Defense Secretary Chuck Hagel and Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey were briefed, as were members of congress, on the infiltration. 

Even in the midst of Iranian president Hassan Rouhani's charm campaign towards the U.S., the relationship between the two countries remains very complicated, something the hacking underlines. The army of Iranian hackers, mainly targeting banking and energy companies in the U.S., has been growing for years, with clear ties to the Iranian government. One recent attack reportedly gave Iran the capability to sabotage power plants. The hacks are partially a response to the continuing sanctions against Iran (something Rouhani's recent willingness to negotiate on Iran's nuclear program is supposed to address), and to the U.S.'s own cyberattack effort on Iran: Stuxnet

Seeing as it takes two to cyberwar, the U.S. has already attempted a few responses to the attacks in recent years. The escalation of Iran's hacking capabilities prompted the U.S. to help a group of unspecified neighbors of Iran combat and prevent future cyberattacks. And according to leaked documents from NSA whistleblower Edward Snowden, the White House also authorized intelligence officials to create a list of potential cyberattack targets overseas.