German newspaper Der Spiegel reports that British spy agency GCHQ set up fake LinkedIn and Slashdot pages to plant malware within Belgacom, a Belgian telecommunications company. Using a method called "quantum insert," the GCHQ was reportedly able to preempt legitimate access to the websites, redirecting the employees to fake sites that compromised their computers. Der Spiegel reports that the GCHQ and NSA were also able to infiltrate the Vienna headquarters of the Organization of Petroleum Exporting Countries (OPEC). The report is the latest based on documents provided by whistleblower Edward Snowden.

On September 20th, Der Spiegel reported that the GCHQ hacked Belgacom under a project codenamed "Operation Socialist," in order to "enable better exploitation" of the telecommunications provider. That report referenced the quantum insert method, also known as a "man in the middle attack," but today's report reveals that the British spy agency was able to spoof LinkedIn and Slashdot to conduct the operation. A LinkedIn spokesman told The Independent that "we were never told about this alleged activity and we would never approve of it, irrespective of what purpose it was used for."

Today's report comes as the GCHQ faces an unprecedented amount of pressure from government officials. While the NSA has faced public hearings for months, British intelligence leaders on Thursday faced public questioning for the first time since this year's intelligence leaks began in June. Like US spy heads, British intelligence officials defended surveillance programs as legal, contained, and necessary for national security, claiming that 34 terror plots had been stopped since the London bombings in 2005.

Update: Slashdot's new parent company, Dice Holdings, provided us the following statement on Monday indicating that if any NSA compromises occurred through Slashdot, they were not known to the website's operators until the news was posted to the site itself on Sunday night. As a Dice Holdings spokesperson said:

"We were alerted to these reported government agency actions by a submission on Slashdot made by the community Sunday evening linking to news stories. To be clear, we have not been asked to cooperate with any government agency related to this matter and have not provided access to Slashdot systems or user information. We know of no unauthorized Slashdot code manipulation, or attempts to effect any. We do not approve of this reported activity and if true, it’s unfortunate that we are yet another in a long line of internet businesses to suffer this type of intrusion." — Jennifer Bewley, Spokesperson, Dice Holdings, Inc.