Cisco Security Intelligence Operations has detected significant activity related to Italian-language spam e-mail messages that claim to contain information about a tax processing fee for the recipient. The text in the e-mail message attempts to convince the recipient to open the attachment and view the details. However, the .zip attachment contains a malicious .exe file that, when executed, attempts to infect the system with malicious code.
E-mail messages that are related to this threat (RuleID4130) may contain any of the following files:
F24_5_5_2012.zip
F24_5_5_2012.exe
The F24_5_5_2012.exe file in the F24_5_5_2012.zip attachment has a file size of 65,536 bytes. The MD5 checksum, which is a unique identifier of the executable, has the following string: 0x3E3C3FC2D729227B085E2A9E9F8CF338
The following text is a sample of the e-mail message that is associated with this threat outbreak:
Message Body:
Gentile Cliente
Con la presente inviamo in allegato la parcella per l'elaborazione della dichiarazione dei redditi per l'anno 2011 da saldare.
Cordiali saluti.
Studio Associato
Delia-Benedetti-Giannotto
La segreteria
Via Antonio Bosio n.28
00161 Roma
The malware associated with this threat outbreak appears to be a trojan that belongs to the Trojan:Win32/Matsnu family, which has the ability to download a malicious file from the Internet and create a start-up registry entry. This trojan could make modifications to the SafeBoot registry key, which could disable safe mode. This trojan could attempt to contact arbitrary hosts on the Internet.
Cisco Security Intelligence Operations analysts examine real-world e-mail traffic data that is collected from over 100,000 contributing organizations worldwide. This data helps provide a range of information about and analysis of global e-mail security threats and trends. Cisco will continue to monitor this threat and automatically adapt IronPort systems to protect customers. This report will be updated if there are significant changes or if the risk to end users increases.
Cisco IronPort Virus Outbreak Filters protect customers during the critical period between the first exploit of a virus outbreak and the release of vendor antivirus signatures. E-mail that is managed by Cisco and end users who are protected by Cisco IronPort web security appliances will not be impacted by these attacks. Cisco IronPort appliances are automatically updated to prevent both spam e-mail and hostile web URLs from being passed to the end user.
Related Links
Cisco Security Intelligence Operations
Cisco Threat Operations Center
Cisco SenderBase Security Network
