BEIJING — Chinese hackers repeatedly penetrated The New York Times' computer systems over the past four months, stealing reporters' passwords and hunting for files on an investigation into the wealth amassed by the family of a top Chinese leader, the newspaper reported Thursday. Security experts hired to investigate and plug the breach found that the attacks used tactics similar to ones used in previous hacking incidents traced to China, the report said. It said the hackers routed the attacks through computers at US universities, installed a strain of malicious software, or malware, associated with Chinese hackers and initiated the attacks from Chinese university computers previously used by the Chinese military to attack US military contractors. The attacks, which began in mid-September, coincided with a Times investigation into how the relatives and family of Premier Wen Jiabao built a fortune worth over $2 billion. The report, which was posted online Oct. 25, embarrassed the Communist Party leadership, coming ahead of a fraught transition to new leaders and exposing deep-seated favoritism at a time when many Chinese are upset about a wealth gap. The hackers eventually lifted the computer passwords of all Times employees and used them. The Chinese foreign and defense ministries called the Times' allegations baseless. “Chinese law forbids hacking and any other actions that damage Internet security,” the Defense Ministry said in a statement. “The Chinese military has never supported any hacking activities. Cyber-attacks are characterized by being cross-national and anonymous. To accuse the Chinese military of launching cyber-attacks without firm evidence is not professional and also groundless.” — AP