MIAMI (CBSMiami.com) – Lockheed Martin, which has facilities in Doral, was the target of a “significant and tenacious” cyber attack the company revealed late Saturday.

Lockheed, one of the largest defense contractors in the country, houses in its computer systems highly sensitive information. But, the company and the Department of Homeland Security said the secrets were not accessed by the hackers.

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The attempted attack underscored how vulnerable much of the United States’ critical defense data, among other areas of critical infrastructure, actually are to hacker attacks.

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Lockheed said it found the attack “almost immediately” and took countermeasures to fend off the hacker attack.

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