The lab credited with discovering the Duqu malware has built an open source toolkit that administrators can use to see whether their networks are infected.
The Duqu Detector Toolkit v1.01 looks for suspicious files left by Duqu, which has created a buzz in the security community given its stealthy nature and some characteristics it shares with another famous piece of malicious software, Stuxnet.
The Laboratory of Cryptography and System Security (CrySys), part of Budapest University of Technology and Economics based in Hungary, wrote in its release notes that the toolkit, which is composed of four components, looks for strange files that mark an infection.
CrySys said that the toolkit should detect a real active Duqu infection, but it is possible to get a false positive, so it cautioned that administrators will need to analyse the results.
Forensic standalone tools such as the one CrySys developed are important since it will give Duqu victims a better image of how they were attacked, said Costin Raiu, director of the global research and analysis team for Kaspersky Lab. Antivirus software does not give the same insight and focuses on instead on detecting and blocking an attack.
"The toolkit released by CrySys Lab is top class," Raiu said. "Of course, all of this can be done 'manually,' but these tools make it much easier to spot anomalies in Duqu-infected computers."
The toolkit also has a component that could let victims figure out what data Duqu has stolen. Costin said stolen data is stored in files ending in "DQ", hence the malware's name, and in "DF".
"I'm sure that any victim wants to know what was stolen from them," Raiu said.
At least one other company has released a detection tool for detecting Duqu. NSS Labs' tool is a script looks for certain strings within drivers employed by Duqu.
Microsoft is in the process of creating a patch for the software vulnerability used by Duqu to infect computers. CrySys is also credited with discovering that Duqu used a previously unknown Windows vulnerability to infect computers after examining an installer file.
A Duqu infection could occur if a person was tricked into opening a malicious Microsoft Word document sent by email to a victim. The vulnerability is in Windows' Win32k TrueType font parsing engine. Microsoft has published a tool to temporarily block attacks until the patch is ready.