Criminal networks of hackers bent on stealing information and extorting money pose a greater threat to multinational companies than any state-sponsored internet attacks, cyber security experts have warned.

The claim comes after the revelation that Foxconn, the Taiwanese company that makes most of Apple’s gadgets, was hacked by criminals seeking to exploit its dispute with a Chinese rival.

Infiltration of security and corporate IT systems is a serious concern for western nations and companies. The US has stepped up pressure on Beijing to combat cyberattacks believed to originate in China, including a warning that it could use trade action to retaliate against online trade secret theft from US companies.