Researchers have unearthed a decade-long espionage operation that used the popular TeamViewer remote-access program and proprietary malware to target high-level political and industrial figures in Eastern Europe.

TeamSpy, as the shadow group has been dubbed, collected encryption keys and documents marked as "secret" from a variety of high-level targets, according to a report published Wednesday by Hungary-based CrySyS Lab. Targets included a Russia-based Embassy for an undisclosed country belonging to both NATO and the European Union, an industrial manufacturer also located in Russia, multiple research and educational organizations in France and Belgium, and an electronics company located in Iran. CrySyS learned of the attacks after Hungary's National Security Authority disclosed intelligence that TeamSpy had hit an unnamed "Hungarian high-profile governmental victim."

Malware used in the attacks indicates that those responsible may have operated for years and may have also targeted figures in a variety of countries throughout the world. Adding intrigue to the discovery, techniques used in the attacks bear a striking resemblance to an online banking fraud ring known as Sheldon, and a separate analysis from researchers at Kaspersky Lab found similarities to the Red October espionage campaign that the Russia-based security firm discovered earlier this year.

"Most likely the same attackers are behind the attacks that span for the last 10 years, as there are clear connections between samples used in different years and campaigns," CrySyS researchers wrote in their report. "Interestingly, the attacks began to gain new momentum in the second half of 2012."

They added: "The attackers surely aim for important targets. This conclusion comes from a number of different facts, including victim IPs, known activities on some targets, traceroute for probably high-profile targets, file names used in information stealing activities, strange paramilitary language of some structures, etc."

The attackers relied on a variety of methods, including the use of a digitally signed version of TeamViewer that has been modified through a technique known as "DLL hijacking" to spy on targets in real-time. Installation of the compromised program also provides attackers with a backdoor to install updates and additional malware. Both the TeamViewer technique and command servers used in the attack harken back to Sheldon. The TeamSpy operation also relies on more traditional malware tools that were custom-built for the purpose of espionage or bank fraud.

According to Kaspersky, the operators infected their victims through a series of "watering hole" attacks that plant malware on websites frequented by the intended victims. When the targets visit the booby-trapped sites, they also become infected. The attackers also injected malware into advertising networks to blanket entire regions. In many cases, much of that attack code used to infect victims was spawned from the Eleonore exploit kit. Domains used to host command and control servers that communicated with infected machines included politnews.org, bannetwork.org, planetanews.org, bulbanews.org, and r2bnetwork.org.

The discovery of TeamSpy is only the latest to reveal an international operation that uses malware to siphon sensitive data from high-profile targets. The most well-known campaign was dubbed Flame. Other surveillance campaigns include Gauss and Duqu, all three of which are believed to have been supported by a well-resourced nation-state. Last year, researchers also uncovered an espionage campaign dubbed Mahdi.