Attacks/Breaches
7/16/2010
01:56 PM
50%
50%

Malware Spreading Via USB Drives

The Stuxnet rootkit launches even with AutoRun and AutoPlay disabled and is known to affect Windows 7 Enterprise Edition x86 operating systems.

Security experts are warning of never-before-seen malware, dubbed Stuxnet, that spreads via USB drives, infecting PCs via an unknown -- aka zero-day -- Windows vulnerability. Unfortunately, the attack works even with AutoRun and AutoPlay disabled, and affects at least Windows 7 Enterprise Edition x86 operating systems.

The malware was first reported by VirusBlokAda, an antivirus company based in Belarus. According to an analysis released by the firm, "You just have to open [an] infected USB storage device using Microsoft Explorer or any other file manager that can display icons, to infect your operating system and allow execution of [the] malware program." Once a PC is infected, the rootkit takes additional steps to then camouflage the .lnk files and its system process threads.

Reportedly, the malware's purpose is to gather any information relating to Siemens SCADA (supervisory control and data acquisition) system software.

But exactly how Stuxnet works remains somewhat unclear. "Although analysis is not complete, it would appear that the flaw is in how Windows Explorer loads the image to display when showing a shortcut," according to Chester Wisniewski, a security expert at antivirus vendor Sophos. "This feature is being used to exploit a vulnerability and execute a DLL to load the malware on the system."

Here's what else is known: The malware uses .lnk files to "to launch files from USB storage devices, a method which hasn't been used before," said Wisniewski. To infect further USB drives, the malware also dynamically generates a new .lnk file for each new USB device. "At this time it is unclear whether this is necessary for the exploit to work, or whether it is a control mechanism for the perpetrators of this attack," he said.

Interestingly, the DLL is disguised as a device driver, which is what allows it to auto-load, thanks to the malware having a valid digital signature from Realtek Semiconductor, a legitimate company. Security researchers are anxious to learn how attackers got their hands on the digital signature, since such signatures are critical for differentiating good software from bad.

As that suggests, "digitally signed malware is a nightmare for antivirus developers," said Aleks Gostev, a security expert at antivirus vendor Kaspersky Lab, in a blog post.

Patching the vulnerability or vulnerabilities exploited by Stuxnet will likely require an operating system fix from Microsoft, rather than simply recalling Realtek's digital signature. "Recalling a certificate from a company like this simply isn't feasible -- it would cause an enormous amount of the software which they've released to become unusable," said Gostev.

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Dark Reading Tech Digest, Dec. 19, 2014
Software-defined networking can be a net plus for security. The key: Work with the network team to implement gradually, test as you go, and take the opportunity to overhaul your security strategy.
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-4632
Published: 2015-01-31
VMware vSphere Data Protection (VDP) 5.1, 5.5 before 5.5.9, and 5.8 before 5.8.1 does not properly verify X.509 certificates from vCenter Server SSL servers, which allows man-in-the-middle attackers to spoof servers, and bypass intended backup and restore access restrictions, via a crafted certifica...

CVE-2014-7287
Published: 2015-01-31
The key-management component in Symantec PGP Universal Server and Encryption Management Server before 3.3.2 MP7 allows remote attackers to trigger unintended content in outbound e-mail messages via a crafted key UID value in an inbound e-mail message, as demonstrated by the outbound Subject header.

CVE-2014-7288
Published: 2015-01-31
Symantec PGP Universal Server and Encryption Management Server before 3.3.2 MP7 allow remote authenticated administrators to execute arbitrary shell commands via a crafted command line in a database-backup restore action.

CVE-2014-8266
Published: 2015-01-31
Multiple cross-site scripting (XSS) vulnerabilities in the note-creation page in QPR Portal 2014.1.1 and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) title or (2) body field.

CVE-2014-8267
Published: 2015-01-31
Cross-site scripting (XSS) vulnerability in QPR Portal 2014.1.1 and earlier allows remote attackers to inject arbitrary web script or HTML via the RID parameter.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
If you’re a security professional, you’ve probably been asked many questions about the December attack on Sony. On Jan. 21 at 1pm eastern, you can join a special, one-hour Dark Reading Radio discussion devoted to the Sony hack and the issues that may arise from it.