Duqu Worm Causing Collateral Damage in a Silent Cyber-War

By Wayne Rash  |  Posted 2011-11-02

Duqu Worm Causing Collateral Damage in a Silent Cyber-War

One of the most sobering things I had to do during my naval career was to check the aim on the big guns on the ship to make sure that the explosive shells fell on the target with sufficient accuracy that they eliminated the target and as little else as possible.

I did this by sitting inside a gun director-a small rotating turret high on the superstructure of the ship. My job was to watch and pull a switch when the aim was right. Then I'd watch the target vanish in a flash.

Besides making sure we hit the right target, I was responsible for reducing as much as possible the collateral damage caused by the explosion. And make no mistake, naval gunfire is highly effective and a miss can cause devastation. Today many of the latest weapons chosen by one state to attack another don't cause explosions. Instead, they disrupt computer systems and sometimes destroy the things those computers control. The damage is just as real, but the shot is silent and it comes seemingly from nowhere.

The first of these weapons was Stuxnet, which was designed to ruin Iran's nuclear production capability by destroying its uranium enrichment centrifuges. Now comes a similar weapon called Duqu. Right now, no one knows for sure who launched Duqu, but like Stuxnet it has created significant collateral damage.

What we do know about Duqu is that it shares a number of common characteristics with Stuxnet. Both worms exploit zero-day vulnerabilities in Windows, but neither really steals anything of monetary value. Both rely on command and control systems located far from where they do their damage. Duqu originally used servers in India, then in Belgium. All of the known command and control services have been shut down.

Fortunately, Stuxnet alerted security researchers around the world to this type of activity, so Duqu was detected in short order by researchers at the Laboratory of Cryptography and System Security at the Budapest University of Technology and Economics. Researchers there discovered the worm and worked with researchers at Symantec to discover its nature and its means of spreading through infected Microsoft Word files.

It's notable that Duqu is apparently designed to gather intelligence that will eventually lead to another Stuxnet-like attack. It includes a keylogger and a means of transmitting the information gathered to another computer. A Symantec white paper contends that the authors of Duqu had access to the Stuxnet source code, which means that they are the same people who created Stuxnet or they are allied with those people.

Duqu Damage Will Continue in Unforeseen Ways


The Duqu worm, which Symantec calls the precursor to the next Stuxnet, has some unique features, including the ability to remove itself from a system if it loses touch with its command and control computer. It's also designed to communicate through a peer-to-peer command and control system as a way to help avoid detection. This and the ability to remove itself in 30 days or so are highly sophisticated features in what is certainly not your average piece of malware.

Now that both of the known command and control computers have been taken offline, it's not clear what will happen with Duqu. It may be that the peer-to-peer feature will eventually lead its reporting network to a new command and control computer, and it's also possible that Duqu has already accomplished what it was designed to do and will simply be allowed to quietly remove itself.

Clearly, the Duqu worm was the second shot in a war that's quietly raging in the world's networks. While we don't know who is waging the war, it's clear that these attacks are coming from somewhere that has the technology to create and now modify an extremely capable attack.

The Duqu worm's installer is concealed in a Word file. That installer can perform its basic functions and then wait for the chance to transmit the information it's gathered. However, unlike Stuxnet, it needs access to the outside world to reach its command and control computers, and as a way to eventually transmit the intelligence it's gathered.

What's also clear is that a Duqu infection can be prevented, despite its zero-day exploit. The installer is a Word document that has to come from somewhere, perhaps attached in an email, and perhaps stored on a USB memory stick. As I explained in an earlier column, all it takes is a little training to teach employees not to open strange attachments and you'll defeat it.

Meanwhile, this worm is circulating all over some parts of the world creating collateral damage along the way. Unlike a weapon that is controlled by someone responsible for the effects when it fires, this weapon, like Stuxnet that proceeded it, is simply sent out with the hope that it'll find its target and produce the required results. It's unclear whether this has happened. What is clear is that this weapon has caused plenty of other damage in the process.

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