According to the U.S. National Security Agency, Chinese cyber activity in the United States has risen in recent months with the bulk of these attacks aimed at disrupting critical infrastructure.

The Wall Street Journal has reported, Chinese hackers have been able to breach and steal a slew of documents,including missile plans, from U.S. Navy contractors of all sizes.

Over the last 18 months, hackers linked to China have successfully conducted multiple breaches to gather intelligence, steal intellectual property and sabotage American systems, said the WSJ report which based itself on information from officials and exports.

According to these sources, Navy Secretary Richard Spencer had ordered a review of cybersecurity weaknesses that led to an initial assessment validating concerns and laying groundwork for a response by the Navy.

The U.S. Navy has called the attacks troubling and unacceptable.

According to Rob Joyce, an official from the U.S. National Security Agency, Chinese cyber activity in the United States has risen in recent months.

Their cyber attacks have targeted a range of U.S. industries including financial, energy, and healthcare sectors. These attacks have gone beyond efforts to spy and steal intellectual property and more into disrupting critical infrastructure.

Chinese officials did not immediately respond to a request for comment but have denied they engage in cyberattacks.