Sage "Outdated Invoice" spam spreads malware via cubbyusercontent.com

This fake Sage email spreads malware using a service called Cubby, whatever that is.

From:     Sage Account & Payroll [invoice@sage.com]
Date:     17 October 2014 10:28
Subject:     Outdated Invoice

Sage Account & Payroll

You have an outdated invoice from Sage Accounting that is ready for payment. To find out more details on this invoice, please follow the link bellow or click here to view/download your account invoice:

https://invoice.sage.co.uk/Account?864394=Invoice_032414.zip


If we hold any information about you which is incorrect or if there are any changes to your details please let us know by so that we can keep our records accurate and up to date. If you would like to update your records or see a copy of the information that we hold about you, you can contact us at Data Protection Officer, Sage (UK) Ltd, North Park, Newcastle-upon-Tyne, NE13 9AA or by email to digital@sage.com. If you request a copy of your information you will need to pay a statutory fee which is currently £10.

The contents of this email and any attachments are confidential. They are intended for the named recipient(s) only. If you have received this email in error please notify the system manager or the sender immediately and do not disclose the contents to anyone or make copies.

We have communicated this information with users as well, and we will continue to communicate with you through email as your transition continues.

This email was sent to: [redacted]

This email was sent by: Sage UK Limited
NC1-002-08-25, Newcastle upon Tyne., North Park, NE13 9AA, United Kingdom

Privacy and Security
Keeping your financial information secure is one of our most important responsibilities. For an explanation of how we manage customer information, please read our Privacy Policy. You can also learn how Sage UK Limited keeps your personal information secure and how you can help protect yourself.

Despite appearances, the link in the email (in this case) actually goes to https://www.cubbyusercontent.com/pl/Invoice_032414.zip/_8deb77d3530f43be8a3166544b8fee9d and it downloads a file Invoice_032414.zip. This in turn contains a malicious executable Invoice_032414.exe which has a VirusTotal detection rate of 3/53. The Malwr report shows HTTP conversations with the following URLs:

http://188.165.214.6:15600/1710uk3/HOME/0/51-SP3/0/
http://188.165.214.6:15600/1710uk3/HOME/1/0/0/
http://188.165.214.6:15600/1710uk3/HOME/41/5/1/
http://tonysenior.co.uk/images/IR/1710uk3.osa

188.165.214.6 is not surprisingly allocated to OVH France. In turn, it drops an executable bcwyw.exe (VT 6/54, Malwr report) which communicates with 66.102.253.25 (a China Telecom address located in the US in a Rackspace IP range) and also moxbk.exe (VT 1/52, Malwr report).

Recommended blocklist:
188.165.214.6
66.102.253.25
tonysenior.co.uk