The attacks that took place in 2014 and this year involved the use of a new version of the Duqu cyberespionage malware, according to antivirus firm Kaspersky Lab, which also found the malware on its own systems.
Kaspersky Lab discovered in early spring that several of its internal systems had been compromised and the subsequent investigation resulted in the identification of what the company now calls Duqu 2.0.
Duqu is a highly sophisticated malware platform used for cyberespionage that was originally found in 2011. It is believed to be related to Stuxnet, the computer worm developed by the U.S. and Israel to sabotage Iran's nuclear program.
Security researchers from different companies tracked Duqu developments for several months after its initial discovery in 2011, but the operation went dark in 2012. This led to a belief that the group behind the malware decided to replace it with something else.
It now turns out that the Duqu creators were actually working on an even more sophisticated version of the malware platform that runs only in the compromised system's memory and doesn't modify disk files or system settings -- Duqu 2.0.
Kaspersky Lab believes that the Duqu 2.0 group first targeted an employee working in one of the company's offices in the Asia and Pacific region, likely through a spear-phishing email. Since the employee's machine was fully patched at the time of the compromise, the company believes that a zero-day exploit was used -- this is an exploit for a previously unknown vulnerability.
The Duqu 2.0 attackers exploited at least one confirmed zero-day vulnerability that was patched by Microsoft on Tuesday, and possibly two other vulnerabilities that are now patched, but had zero-day status when the group was using them, the Kaspersky researchers said in a report released Wednesday.
Zero-day exploits are extremely valuable for attackers and very expensive to buy on the black market. The use of multiple such exploits coupled with the malware platform's complexity -- over 100 plug-ins implementing different functionality -- enforces the belief that Duqu 2.0 is the work of a nation state.
After discovering the infection on its own systems, Kaspersky scanned its global customer base and discovered Duqu 2.0 infections at several hotels that hosted negotiations between Iran and the U.S., Germany, France, Russia, the U.K. and China (P5+1) to find a diplomatic solution that would ensure that Iran's nuclear program is exclusively peaceful. A Duqu 2.0 attack was also associated with an event organized on the 70th anniversary of the liberation of the Auschwitz-Birkenau concentration camp.
The techniques used by the Duqu 2.0 group are, according to the Kaspersky researchers, ahead of anything seen in the advanced persistent threat world.
Its level of sophistication surpasses even the Equation group, which until now has been considered the most sophisticated cyberespionage actor, the Kaspersky researchers said.
Unlike the Equation malware, which uses persistence mechanisms on infected systems, Duqu 2.0 was designed to run only in memory and disappears on reboot. This suggests that its authors know they can regain access to previously compromised systems and reinfect them.
"The Duqu 2.0 threat actor was confident enough to create and manage an entire cyberespionage operation just in memory -- one that could survive within an entire network of compromised computers without relying on any persistence mechanism at all," the Kaspersky researchers wrote.
Most malware creators, including sophisticated ones like the Equation group, are consistent in their use of particular encryption algorithms. With Duqu 2.0, the encryption algorithms used vary from case to case, making it more difficult to establish relationships between infections.
Kaspersky Lab did not speculate on which country might be behind Duqu 2.0, but the Wall Street Journal reported that unnamed former U.S. government officials believe it's Israel.