Over 70 organizations including the United Nations and major US defense groups have been targets of a global cyber spying effort, according to security firm McAfee, with analysts pointing to China as the culprit, the Washington Post said Wednesday.

Targets for the intrusions -- identified from logs tracked to a single server -- included computer networks of the United Nations secretariat, a US Energy Department lab, and some dozen US defense firms, said the McAfee report to be released Wednesday, according to the Post.

The snooping appeared to have been ongoing for several years.

The report identified 72 compromised organizations in all, 49 of which were located in the United States, said the Post.

Intruders, according to the McAfee report, sought sensitive data on US military systems and satellite communications, among other prizes.

Cybersecurity experts told the Post that China was the most likely culprit, as much of the intruders' targets listed by McAfee put emphasis on organizations linked to Taiwan and the International Olympic Committee (IOC) in months leading up to the 2008 Beijing games.

However McAfee, a leader in the cyber security industry, tracking network intrusions around the world, did not openly blame Beijing.