Duqu malware is making waves in the security world at the moment. It is an attack that uses a zero-day to exploit a vulnerability in the windows kernel, more specifically it targets the Win32k TrueType font parsing engine. The reason why its big news is because its a highly sophisticated attack on specific organisations that steals digital certificates, keystrokes, and other systems information. While the specific organisations that have been targeted haven’t been made public, they all dealt with highly sensitive things such industrial control systems. The infection usually began with a .doc dropper file that was emailed and socially engineered to be something that the targeted user would open.
So security experts have began to conjecture that Duqu was developed and executed by the same people responsible for Stuxnet. The reason being that they share a lot in common. They both exploited zero-days relating to the windows kernel, both are signed using stolen certificates, and they both have been highly sophisticated attacks directed at specific organisations. Not only does the profile of the attack match Stuxnet but so does the source code. Where Stuxnet and Duqu start to differ is that Stuxnet was created to act autonomously while Duqu is reliant on command and control servers. Stuxnet targeted industrial machines while Duqu is attacking computer systems.
There are many features that add to Duqu’s sophisticated nature that raises it above the level of ordinary malware. One is that its able to communicate through server message blocks, the protocol that allows networked resources to interact. This allowed Duqu to infect systems that weren’t connected to the internet but were on a network with devices that were. On top of that it was able to receive and transmit message from the C&C server by transmitting the data to a computer connected to the internet and then through SMB to the device on the network that didn’t have internet access. Even the C&C servers themselves show a high level of dedication because they used a unique C&C server for each individual attack. So far only two have been discovered with one in India and one in Belgium. To avoid detection on infected systems it uses 54×54 jpeg files as containers to store stolen data. This way the network traffic wouldn’t show important data moving around just jpeg files. After 30 days of running on the system Duqu deletes itself hiding anyway of detecting it had been there.
So what I most likely think is that Duqu was created and used by the same people who did Stuxnet, and due to the level of sophistication and scale it was most likely a state actor. The state actor probably being a collaboration between the USA and Israel. As of right now Microsoft still hasn’t fixed the vulnerability that allows it. For most users this isn’t that big of a deal because the exact method of the zero-day isn’t known so Duqu’s the only one using it. So unless you happen to be part of large organization then the threat and danger from Duqu is minimal.