Cisco Security has detected significant activity related to spam email messages that claim to contain a tax return notification for the recipient. The text in the email message attempts to persuade the recipient to open the attachment to view details. However, the .zip
attachment contains malicious .exe
file, that when executed, attempts to infect the system with malicious code.
Email messages that are related to this threat (RuleID858KVR) may contain the following files:
file has a file size of 29,696 bytes. The MD5 checksum, which is a unique identifier of the executable, is the following string: 0xB70B79F904984165FB0E3E8AE6B6CF8B
The Tax Report.xls.exe
file in the Tax Report.zip
attachment has a file size of 80,384 bytes. The MD5 checksum is the following string: 0x6FE4D3639767FF5376EE62BEE3CA862D
file in the Your_2013_TaxReturnReport.zip
attachment has a file size of 224,768 bytes. The MD5 checksum is the following string: 0x459910B4C3ECFF73C8505B1AB0ADC5EC
The docs2515.scr file in the docs.zip attachment has a file size of 22,016 bytes. The MD5 checksum is the following string: 0x8042EAF499CE340E614E12F711A07309
The following text is a sample of the e-mail message that is associated with this threat outbreak:
Subject: IRS notification letter
Department of Tresaury Internal Revenue Source
Important information about your tax return
Subject: Tax Agent Report - Delayed Tax Returns
Please do not respond to this email
Tax agent report for delayed tax returns over 30 days
Please find attached your weekly report for the period ending 10/01/2013
What you need to do
Refer to the initial notification email with attachment we sent you with instructions on how to interpret your tax agent report.
Deputy Commissioner of Taxation
Subject: 2013 Tax Return Report!
Your 2013 tax return is under investigation, attached is a copy of the report. Kindly download, read and get back to us as soon as possible
Internal Revenue Service
Subject: FW: Important docs
We have received this documents from your bank, please review attached documents.
Wells Fargo Accounting
Cisco Security analysts examine real-world email 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 email security threats and trends. Cisco will continue to monitor this threat and automatically adapt systems to protect customers. This report will be updated if there are significant changes or if the risk to end users increases.
Cisco Virus Outbreak Filters protect customers during the critical period between the first exploit of a virus outbreak and the release of vendor antivirus signatures. Email that is managed by Cisco and end users who are protected by Cisco web security appliances will not be impacted by these attacks. Cisco appliances are automatically updated to prevent both spam email and hostile web URLs from being passed to the end user.
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