Lockheed Martin Corp, the No 1 provider of information technology to the US government and the top Pentagon supplier, said has said that the number of sophisticated cyber campaigns aimed at its computer networks had more than quadrupled since 2007.

The weapons maker had identified 43 distinct organisations that were actively targeting Lockheed's networks this year, and the number could rise, Chandra McMahon, vice president for commercial markets at Lockheed's information systems business, told the Reuters Cybersecurity Summit in Washington.

That compares with 10 campaigns directed against Lockheed, which builds the F-35 fighter jet, satellites and warships, in 2007, and 28 in 2010, she said.

Lockheed and other US weapons makers are frequent targets of criminal groups, nation states and other hackers seeking to extract valuable information about high-end weapons systems.

US intelligence reports have cited attacks launched by groups in Iran, China, Russia and North Korea. Lockheed declined comment on any specifics about the campaigns it had identified.

McMahon said the company had seen a 20 percent increase in cyber campaigns - complex attacks by organizations with specific tactics and procedures - in 2013 alone.

Eight of the 10 campaigns identified in 2007 were still active, she said, and six of the campaigns identified by Lockheed were now being tracked by US cyber officials.

Lockheed provides a wide range of cyber services for the US military and other government agencies, as well as energy companies, utilities and other critical infrastructure firms.

Hackers were using some of the techniques and tactics initially targeted at US weapons makers against companies in other sectors to steal data, disrupt networks and even damage equipment, McMahon said.

Lockheed said it was seeing increasing interest among private-sector companies in beefing up their security given the growing number of attacks on US computer networks.

The company cited increased evidence of malware targeted at industrial control systems at utility companies, although McMahon said Lockheed had not seen physical damage caused by a cyber attack in the utility networks.

"While we haven't seen specific action on objectives in terms of damage, what we have seen over the last several years (is) malware created and deployed to damage critical infrastructure," McMahon said.

She said she expected "steep increases" in cybersecurity investments by private-sector companies in coming years, and Lockheed expects double-digit growth in its cyber business, which now accounts for 10 percent of revenues in the $8 billion information systems sector. - Reuters