The Pentagon plans to boost the number of personnel assigned to fighting cyberattacks dramatically over the next few years to 4,900 from only 900 now, after requests from the head of its Cyber Command, Gen. Keith Alexander, who also heads the National Security Agency.

The move follows outgoing Defense Secretary Leon Panetta’s warning last October that the country could face the prospect of a “cyber Pearl Harbor" that would not only attack computer systems but also power grids, transportation and financial networks.

Subsequently, there were reports of major attacks on the computers of enterprises including Saudi Aramco, major U.S. banks including Bank of America (NYSE:BAC), as well as various government agencies.

Panetta and other security officials have warned of increased danger of attacks from Iran and terrorist organizations. Privately, they have warned about threats from nations including China and Russia.

The manpower request was reported by the Washington Post, which added the new mission will see three new types of Cyber Command forces. A “national mission force” would protect computer systems for infrastructure such as power plants critical to national and economic security, “combat mission forces” would help commanders prepare responses to cyberattacks, and “cyber protection forces” would help protect the Department of Defense and other networks.

Currently, most of the government’s cybersecurity programs are not public, but the Department of Homeland Security, through its U.S. Computer Emergency Readiness Team, maintains a constant public list of threats and advisories at

Earlier in January, it was that site that warned against potential flaws in the Java programming language now maintained by Oracle Corp. (NASDAQ:ORCL), the No. 1 database company, and also warned about potential flaws in Internet Explorer from Microsoft Corp. (NASDAQ:MSFT), the No. 1 software company.

The Homeland Security team handles confidential alerts about cyber threats and also works with the top developers of security software such as Symantec Corp. (NASDAQ:SYMC) and the McAfee unit of Intel Corp (NASDAQ:INTC) the No. 1 software company.

The Pentagon generally declines to comment on cyberattacks and cyber warfare. Last year’s “Confront and Conceal: Obama’s Secret Wars and Surprising Use of American Power” by David Sanger, a reporter for the New York Times, disclosed many examples of cyberwarfare such as the apparent insertion of the “stuxnet” worm into Iranian atomic computer complexes and a plan called “Olympic Games” to thwart hackers.

Former Nebraska Sen. Chuck Hagel, a Republican, has been nominated by President Barack Obama to succeed Panetta at the Pentagon. He may be asked about the new cyberwarfare plans at his confirmation hearing before the Senate Armed Services Committee, scheduled to begin on Thursday.