Published:
23 July 2010
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT Security Bulletin ASB-2010.0174.4 Malware targeting Siemens Simatic software 23 July 2010 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Siemens Simatic WinCC and PCS 7 Impact/Access: Unauthorised Access -- Unknown/Unspecified Resolution: Patch/Upgrade CVE Names: CVE-2010-2772 Member content until: Thursday, August 19 2010 Revision History: July 23 2010: Added CVE reference July 23 2010: Security patch and virus removal tool released July 20 2010: Marked as an alert July 20 2010: Initial Release OVERVIEW Siemens has released a statement verifying that malware, exploiting an unpatched vulnerability in Microsoft Windows Shell, is targeting Siemens Simatic software WinCC and PCS 7. [1] Siemens have now made available a SIMATIC Security Update and a virus removal tool. [2] IMPACT The impact on Siemens SCADA software is presently unconfirmed. Siemens is investigating the issue. [1] The vulnerability in Microsoft Windows Shell may be leveraged to execute arbitrary code as the logged on user. For more information about the vulnerability in Microsoft Windows Shell, see AusCERT ESB-2010.0628. [3] MITIGATION Siemens recommends that customers carry out an active check of their computer systems with WinCC installations. According to Siemens, TrendMicro, McAfee and Symantec have updates that detect the malware. Microsoft provides workarounds for the vulnerability in Windows Shell. These include the disabling of icons for shortcuts and disabling the WebClient service. See AusCERT ESB-2010.0628 for more information. [3] Running with reduced privileges will limit the extent of infection and AusCERT recommends the use of limited user accounts for day-to-day activities. AusCERT also recommends enabling software restriction policy, via a Group Policy object, to prevent unwanted software from executing. Although not a mitigation against this attack, it is best practice to disable Autorun to prevent automatic execution of an infected device. [4] TrendMicro has developed a tool to detect and remove the malware, which is currently available from the Siemens website. [2] Siemens have released a SIMATIC Security Update which is also available to dowload from their website. [2] REFERENCES [1] Update on Virus Affecting Simatic WinCC SCADA Systems http://www.sea.siemens.com/us/News/Industrial/Pages/WinCC_Update.aspx [2] Tool now available to detect and remove virus http://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&lang=en&objid=43876783&caller=view [3] AusCERT ESB-2010.0628 - Vulnerability in Windows Shell CouldAllow Remote Code Execution http://www.auscert.org.au/13075 [4] How to disable the Autorun functionality in Windows http://support.microsoft.com/kb/967715 AusCERT has made every effort to ensure that the information contained in this document is accurate. However, the decision to use the information described is the responsibility of each user or organisation. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iD8DBQFMSQjc/iFOrG6YcBERAo6PAJ9Y5686cWe+nB5E8pKEFI2CNSFjSwCgtr/t LEFiIeTWcDeG2A9NbEXHzRw= =7YsI -----END PGP SIGNATURE-----