Malware spam: "Your 2015 Electronic IP Pin!" / "Internal Revenue Service [refund.noreply@irs.gov]"

This fake IRS email comes with a malicious attachment.

From:    Internal Revenue Service [refund.noreply@irs.gov]
Date:    6 March 2015 at 08:48
Subject:    Your 2015 Electronic IP Pin!

Dear Member

This is to inform you that our system has generated your new secured Electronic PIN to e-file your 2014 tax return.

Please kindly download the microsoft file to securely review it.

Thanks

Internal Revenue Service
915 Second Avenue, MS W180

So far I have only seen a single sample of this with an attachment TaxReport(IP_PIN).doc - although there are usually several different versions. Currently this is undetected by AV vendors. This contains a malicious macro [pastebin] which downloads a component from the following location:

http://chihoiphunumos.ru/js/bin.exe

There are probably other download locations, but the payload will be the same. This is saved as %TEMP%\324235235.exe and has a detection rate of 1/55. Automated analysis tools [1] [2] show attempted connections to:

92.63.87.13 (MWTV, Latvia)
95.163.121.200 (Digital Networks CJSC aka DINETHOSTING, Russia)
104.232.32.119 (Net3, US)
87.236.215.103 (OneGbits, Lithunia)

According to the Malwr report this executable drops another version of itself [VT 1/56] and a malicious DLL [VT 2/56].

Recommended blocklist:
92.63.82.0/23
92.63.84.0/22
92.63.88.0/24
95.163.121.0/24
104.232.32.119
87.236.215.103