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Friday 15 January 2016

Malware spam: "Scanned image from MX-2640N" / cm_sharpscan@yahoo.co.uk

This fake document spam is meant to have a malicious attachment, but all the versions I have seen are corrupt.
From:    cm_sharpscan@yahoo.co.uk
Date:    15 January 2016 at 10:12
Subject:    Scanned image from MX-2640N

Reply to: cm_sharpscan@yahoo.co.uk [cm_sharpscan@yahoo.co.uk]
Device Name: Not Set
Device Model: MX-2640N
Location: Not Set

File Format: DOC (Medium)
Resolution: 200dpi x 200dpi

Attached file is scanned image in Microsoft Word format.
The attachment is meant to be in the format username@domain.tld_201601151152_097144.doc but due to an apparent error in the MIME formatting, saving it results in a file in the format _username@domain.tld_201601151152_097144.doc_  0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAPgADAP7_CQAGAAAAAAAAAAAAAAACAAAAKgAAAAAA.doc_0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAPgADAP7_CQAGAAAAAAAAAAAAAAACAAAAKgAAAAAA instead

The next problem for the bad guys is that they have added a leading space to the Base 64 encoded section with the attachment in. This means that unless the mail client somehow fixes the error, the attachments are harmless (VirusTotal results [1] [2] [3] [4]).

Now, not many people are going to wade in and fix the malicious attachments, but I did and I got three unique files (VirusTotal results [1] [2] [3]).

Analysis of these documents is pending, but the payload is probably meant to be the Dridex banking trojan.

UPDATE

I managed to coax a Hybrid Analysis of two of the documents [1] [2] showing download locations of:

nasha-pasika.lviv.ua/786585d/08g7g6r56r.exe
arm.tv/786585d/08g7g6r56r.exe


This executable is the same one dropped in this spam run. It currently has a VirusTotal detection rate of 6/54.

Ironically, that Ukrainian site is on 91.217.91.18 (PE Ivanov Vitaliy Sergeevich, Ukraine) and it is the only time I have seen a legitimate site in the block.. and it has been hacked. In any case, I would recommend blocking the entire 91.217.90.0/23, legitimate sites or not.

Those two Hybrid Analysis reports give a whole bunch of callback IPs between them:

88.208.35.71 (Advanced Hosters B.V., NL)
216.117.130.191 (Internet Technologies Inc., US)
116.12.92.107 (Lanka Comunication Services, Sri Lanka)
46.32.243.144 (Heart Internet VPS, UK)
195.96.228.199 (Bulgarian Academy Of Sciences, Bulgaria)
161.53.144.25 (Veleuciliste U Sibeniku, Croatia)
41.38.18.230 (TE Data, Egypt)


Despite the fact that the attachments aren't working, I would expect to see those IPs in use for other badness and I would recommend blocking them.

Recommended blocklist:
88.208.35.71
216.117.130.191
116.12.92.107
46.32.243.144
195.96.228.199
161.53.144.25
41.38.18.230

6 comments:

Unknown said...

sample a points to http://149.156.208.41/~s159928/786585d/08g7g6r56r.exe

Unknown said...

sample b points to http://nasha-pasika.lviv.ua/786585d/08g7g6r56r.exe

Unknown said...

sample c points to http://arm.tv/786585d/08g7g6r56r.exe

Unknown said...

files are all the same

Admin said...

I just got it on my professional email account. Thanks for the information

Alan said...

Is it possible to provide steps on how to decode the attachment and recreate the proper attachment?