Potentially Serious Threat Targets Control Systems
According to Byres Security Inc., a new family of threats called Stuxnet appears to be directed specifically at Siemens WinCC and PCS7 products via a previously unknown Windows vulnerability. Byres also discovered a concerted Denial of Service attack against a number of the SCADA information networks such as SCADASEC and ScadaPerspective mailing lists, knocking at least one of these services off line.
Eric Byres, P.E., and Chief Technology Officer of Byres, offers these facts:
• This is a zero-day exploit against all versions of Windows including Windows XP SP3, Windows Server 2003 SP 2, Windows Vista SP1 and SP2, Windows Server 2008 and Windows 7.
• There are no patches available from Microsoft at this time (There are workarounds, which I will describe later).
• This malware is in the wild and probably has been for the past month.
• The known variations of the malware are specifically directed at Siemens WinCC and PCS7 Products.
• The malware is propagated via USB key. It may be also be propagated via network shares from other infected computers.
• Disabling AutoRun does not help! Simply viewing an infected USB using Windows Explorer will infect your computer.
• The objective of the malware appears to be industrial espionage; i.e. to steal intellectual property from SCADA and process control systems. Specifically, the malware uses the Siemens default password of the MSSQL account WinCCConnect to log into the PCS7/WinCC database and extract process data and possibly HMI screens.
The only known workarounds are:
• NOT installing any USB keys into any Windows systems, regardless of the OS patch level or whether AutoRun has been disabled or not
• Disable the displaying of icons for shortcuts (this involves editing the registry)
• Disable the WebClient service
Byres and his team have written a short white paper called “Analysis of Siemens WinCC/PCS7 Malware Attacks.” www.tofinosecurity.com/professional/siemens-pcs7-wincc-malware . If you would like to download the white paper, you will need to register on the website. Byres notes that the whitepaper is in a secure area. People who are already www.tofinosecurity.com web members do not need to reregister.