After lying low for several months, the Chinese military's hacking division has reportedly resumed attacks on U.S. businesses and government agencies.

Earlier this year a US security firm published a report that linked cyber attacks to a Shanghai-based residence. Given that the building is known to belong to the Chinese army, it was widely concluded that China's military was directly involved in the operation.

Chinese officials denied the claims. However, security experts continued to insist that the Shanghai-based unit was responsible for attacking U.S. government agencies, businesses that competed with Chinese firms, and organizations involved in U.S. infrastructure and security.

Chinese Hackers Disengage -- But Not For Long

The New York Times has now asked Mandiant, the security firm behind the original report, to check up on the hackers' activity. After investigating the issue, Mandiant concluded that the hackers not only stopped collecting information in February, but removed spyware it had installed on target machines. (Source: nytimes.com)

However, Mandiant also found that the hackers had resumed operations in March. The strength of their attacks continues to rise.

Meanwhile, the Washington Post says government officials, speaking on condition of anonymity, have provided details about an attack by Chinese sources on Google in 2010. (Source: washingtonpost.com)

The government officials say the FBI and Department of Justice had to engage in a lengthy argument with Google to force it to provide more information about the breach.

Hackers Seek Details Of Gmail Surveillance

According to the officials, the attack was designed to target a database of Gmail account holders for which courts had issued surveillance orders.

It would appear that the hackers were trying to find out which Chinese spies were being monitored by the United States government.

Neither Google nor the FBI were prepared to speak publicly about these claims.