The attacks on Apple, Facebook, Twitter and others are now linked to "an Eastern European gang of hackers that is trying to steal company secrets," according to Bloomberg, citing unnamed people familiar with an ongoing investigation.
"Investigators suspect that the hackers are a criminal group based in Russia or Eastern Europe, and have tracked at least one server being used by the group to a hosting company in the Ukraine," the report said. "Other evidence, including the malware used in the attack, also suggest it is the work of cyber criminals rather than state-sponsored espionage from China, two people familiar with the investigation said."
An earlier report from The New York Times had instead linked recent attacks on companies like Facebook to the Chinese Army. It claimed that there was "little doubt" that an "overwhelming percentage of attacks on American corporations, organizations and government agencies" originate from a People's Liberation Army group known as "Unit 61398" based out of the outskirts of Shanghai.
Apple announced on Wednesday that some of its employees' laptops had been infected through a vulnerability in the Java plug-in for browsers. The company revealed that the same malware was used against a number of companies, but did not indicate what country the attacks may have originated from.
"We identified a small number of systems within Apple that were infected and isolated them from our network," the company said in a statement. "There is no evidence that any data left Apple. We are working closely with law enforcement to find the source of the malware."
The attacks are believed to have occurred through an iPhone developer community website that was hosting malware. It's believed that the infected code made its way onto the computers of Apple, Facebook, Twitter and other companies utilizing a Java zero-day flaw.
The method used by the criminals is a so-called "watering hole attack," in which hackers compromise a popular website that many people visit and trust.
Apple on Tuesday pushed out an update for all OS X users that patches the exploit, and also removes the Java Web applet.