If the Chinese state is really hacking the world as notables such as Google's Eric Schmidt have suggested, which organisations is it using to do the dirty work?
US security consultant Mandiant believes it has come up with the name of the most important culprit, 'PLA 61398', which it identifies in a new report as being the Chinese state's elite cyber unit for carrying out economically-motivated Advanced Persistent Threat (APT) attacks.
If 'PLA 61398' sounds anonymous, Mandiant also supplies its more long-winded formal title, the 2nd Bureau of the People's Liberation Army General Staff Department's (GSD) 3rd Department, or simply by its military designation, 'APT1' or 'Unit 61398'.
For the first time since alleged Chinese cyberattacks were officially added to the US geo-political agenda in 2010, the world can put a name to what has been going on.
This unit alone - one of around 20 such military units operating in China - had conducted 141 attacks across 20 industries in the last seven years, although this is probably only a fraction of its true activity, Mandiant said.
Its mission was to steal intellectual property, business plans, price lists, contact lists and partner agreements. It succeeded, wildly, siphoning 6.5 Terabytes of data from a single victim in 10 months and compromising 17 organisations in January 2010 alone, the firm added.
"From our observations, it is one of the most prolific cyber espionage groups in terms of the sheer quantity of information stolen. The scale and impact of APT1's operations compelled us to write this report."
China Telecom had supplied fibre to a 12-storey 130,000 square foot building in the Pudong New Area in Shanghai built to house the unit in 2007, the firm claimed. This was staffed hundreds of well-trained English-speaking hackers.
A BBC TV crew managed to film the exterior of the unremarkable building before reportedly being stopped by police.
Evidence for the extraordinary accusations? According to Mandiant, many of the IP addresses could be traced back quite easily to networks emanating or controlled from this building and the APT1 group had left its fingerprints on numerous attacks.
Individual cyber-hacking 'authors' appeared to have a degree of autonomy, including 'UglyGorilla', 'DOTA', and 'SuperHard', leaving evidence of their personal involvement over different malware and cyber-campaigns.
"The sheer scale and duration of sustained attacks against such a wide set of industries from a singularly identified group based in China leaves little doubt about the organization behind APT1," said Mandiant.
Mandiant had taken the decision to publish details of PLA 61398's attack designs in order to help defend against them, at least in the short run.
"It is our sincere hope, however, that this report can temporarily increase the costs of Unit 61398's operations and impede their progress in a meaningful way."
Not coincidentally, two weeks ago several US newspapers, including the New York Times, accused China of attempting to hack the emails of its journalists, the scale of which was brought to light after Mandiant itself had been brought in to monitor the attacks.