Citing unnamed officials, the newspaper said the conclusion is contained in the National Intelligence Estimate, a classified report that represents the consensus view of the US intelligence community.
The report identifies China as the country most aggressively seeking to penetrate the computer systems of US businesses and institutions to gain access to data that could be used for economic gain, the paper said.
The document, according to the Post, identifies energy, finance, information technology, aerospace and automotive companies as the most frequent targets of cyber-attacks.
Outside experts have estimated the damage to the US economy in the tens of billions of dollars, the paper said.
The National Intelligence Estimate names three other countries — Russia, Israel and France — as having engaged in mining for economic intelligence but makes clear that cyber-espionage by those countries pales in comparison with China’s effort, the paper notes.
The administration of President Barack Obama is trying to counter the electronic theft of trade secrets by lodging formal protests, expelling diplomatic personnel, imposing travel and visa restrictions, and complaining to the World Trade Organization, the Post said.