GCHQ allegedly employed a "quantum insert" technique to target employees at two Global Roaming Exchange (GRX) providers, sending them to fake websites and compromising their computers. The attack targeted administrators and engineers at GRX firms Comfone and Mach - now owned by Syniverse.
The news follows earlier reports of GCHQ apparently hacking Belgian telecoms firm Belgacom under a project codenamed "Operation Socialist," in September.
According to Der Spiegel, GCHQ used spoofed LinkedIn and Slashdot pages to serve malware to targets. This type of attack was also used to target the Vienna headquarters of the Organisation of Petroleum Exporting Countries, the German newspaper said.
GCHQ's alleged tactics have been condemned by some experts, who say it is undermining the UK's claims that it only targets suspected wrongdoers. Jim Killock, executive director Open Rights Group, said the latest revelations are an example of what was missing from the Parliament's Intelligence and Security Committee (ISC)'s debate last week.
"It is a very serious concern if you are hacking into a neighbouring state's telecoms provider," he told SCMagazineUK.com. "There are treaties between states; they are saying that none of that was helpful, so you wonder what their objective actually was. It will undermine the credibility of the UK."
Killock thinks that the tension is set to continue, commenting: "It is in the Government's interest to give bodies such as GCHQ flexibility; but this also gives them an interest in not fixing these problems. I'm sure this will continue to build until the Government responds with measures to handle it. It is not going to go away, whether it spirals or continues to be a constant thorn it its side."
The breach highlights the ease in which companies can be compromised, Jon Inns, director of product management at security company Accumuli, told SCMagazineUK.com. “Organisations now have to accept that a level of compromise will occur if someone tries hard enough."
The news highlights the need for firms to protect themselves, Alex Raistrick, VP Western Europe at Palo Alto Networks, agreed, saying: "For news sites like LinkedIn, it ought to be common knowledge that hacktivists and cyber criminals have them in their sights. Mitigating these attacks requires a complete approach to cyber security capable of blocking all types of malicious traffic and content, as well as proactive testing of any unknown files or traffic to expose hidden threats."