Computer security firms Kaspersky Lab and CrySyS Lab discovered that the malware, dubbed “MiniDuke,” targeted government computers in the Czech Republic, Ireland, Portugal and Romania along with think tanks, research institutes and healthcare providers in the United States.
“The technical indicators from our analysis show this is a new type of threat actor that hasn’t been seen before,” Kurt Baumgartner, a senior security researcher with Kaspersky Lab, told RT.
Although experts avoid speculating on who the attackers may be, Baumgartner clarified that “based on the target victims and the functionality of the malware” the objective of MiniDuke’s authors is “to collect geopolitical intelligence.”
The threat operates on low-level code to stay hidden, and uses Twitter and Google to get instructions and updates. It allegedly infected PCs when ‘victims’ opened a cleverly disguised Adobe PDF attachment to an email.
“The high level of encryption in the malware and the flexible system it used to communicate with the C2 via Twitter and Google indicates this was a strategically planned operation,” Baumgartner said.
The PDF documents were specifically tailored to their targets, according to the researchers. The attachments referred to highly relevant topics subjects like “foreign policy,” a “human rights seminar,” or “NATO membership plans.”
When the files were opened, MiniDuke would install itself on the user’s computer.
So far it is only known that the malware then connects to two servers, one in Panama and one in Turkey, but security researchers say there are no clear indications of who was behind the online attacks.
According to Karpersky Lab the spyware was written in “assembler language,” a low-level code where each statement corresponds to a specific command, and is very small in size, only 20 kilobytes. Assembler language codes are written specifically for each system they are meant to attack, as opposed to higher-level codes, which can infect multiple types of technologies.
The way the malware was created and used indicates that the attackers “have knowledge from the elite, ‘old school’ type of malicious programmers who were extremely effective at creating highly complex viruses in the past,” Baumgartner says. “MiniDuke’s attackers have combined these skills with the newly advanced sandbox-evading exploits to target high-profile victims, which is unique and something we haven’t seen before.”
MiniDuke is a three-stage attack, technology news and information website, Arstechnica, explains. First it tricks a victim into opening an authentic-looking PDF document, and then infected machines start using Twitter or Google “to retrieve encrypted instructions showing them where to report for additional backdoors.”
“These accounts were created by MiniDuke’s Command and Control (C2) operators and the tweets maintain specific tags labeling encrypted URLs for the backdoors,” Kaspersky Lab said in a statement. “Based on the analysis, it appears that the MiniDuke’s creators provide a dynamic backup system that also can fly under the radar – if Twitter isn’t working or the accounts are down, the malware can use Google Search to find the encrypted strings to the next C2.”
Stages two and three are hidden inside a GIF image file which is downloaded from the command server and “disguised as pictures that appear on a victim’s machine.”