Monday's hack of Twitter and YouTube accounts belonging to U.S. Central Command was embarrassing, but it doesn't appear to have compromised any classified information.
"CENTCOM's operational military networks were not compromised and there was no operational impact to U.S. Central Command," said Navy Commander Elissa Smith, a Pentagon spokeswoman.
Smith said the military is viewing the incident "purely as a case of cybervandalism." But, she said, the Pentagon has notified law enforcement about "the potential release of personally identifiable information."
The hackers posted messages supporting the Islamic State, or ISIS. Some of the messages included publicly available information, such as names and addresses of generals.
The accounts have now been suspended.
The attack came just as President Obama was giving a speech at the Federal Trade Commission on the importance of cybersecurity. Hackers, Obama said, are a "direct threat to the economic security of American families." Cybersecurity is expected to be a major focus in the president's State of the Union address next week.
The hack of the military social-media accounts is yet another reminder that no one is immune from a cyberattack. But cybersecurity experts note that the incident doesn't appear to be nearly as significant as the recent attacks on Sony, Target, Home Depot, or JPMorgan Chase, in which the hackers were able to steal sensitive information.
"It doesn't strike me as particularly significant," said Adam Segal, a senior fellow at the Council on Foreign Relations. "I think it's just irony and embarrassment, especially since the president was speaking about cybersecurity at the same time. But I don't see it as reflecting any new capability or threat."
The hackers likely sent a scam email to trick a person managing the accounts into revealing the password, Segal said.
Michael McNerney, a former Defense Department cybersecurity adviser, said that U.S. operations have weakened ISIS, but that cyberattacks like the one on the CENTCOM accounts can help their recruiting efforts.
"This hack, while not devastating from a security perspective, is a public relations coup for them," he said.
House Homeland Security Chairman Michael McCaul, a Texas Republican, called the incident "severely disturbing."
"Assaults from cyber-jihadists will become more common unless the administration develops a strategy for appropriately responding to these cyberattacks—including those like the North Korea attack against Sony," McCaul said in a statement. "Without laying out the rules of the game for offensive responses and having direct consequences, cyber threats and intrusions from our adversaries will continue and escalate."