WASHINGTON (AP) -- The powerful attack that overwhelmed computers at U.S. and South Korean government agencies for days was even broader than realized, also targeting the White House, the Pentagon and the New York Stock Exchange.

An early analysis of the malicious software used in the attack found its targets also included the National Security Agency, Homeland Security Department, State Department, the Nasdaq stock market and The Washington Post. Many of the organizations appeared to successfully blunt the sustained attacks.

The Associated Press obtained the target list from security experts analyzing the attack. It was not immediately clear who might be responsible or what their motives were.

The attack was remarkably successful. Some of the affected government Web sites -- such as the Treasury Department, Federal Trade Commission and Secret Service -- were still reporting problems days after it started during the July 4 holiday.