Malware spam: "Companies House - new company complaint" / noreply@companies-house.me.uk / noreply@companieshouses.co.uk leads to TrickBot

This fake Companies House spam leads to TrickBot malware:

From:    Companies House [noreply@companieshouses.co.uk]
Date:    2 November 2016 at 11:51
Subject:    Companies House - new company complaint
Signed by:    companieshouses.co.uk

Investigations and Enforcement Services

This message has been auto-generated in response to the company complaint submitted to our WebFiling  service.

The submission number is ID109202DLK02911

Please find the attached document for your review.

Note: This email was sent from a notification-only email address which cannot accept incoming email. Please do not reply directly to this message.

Crown Logo
Companies House
Crown Way
Cardiff
CF14 3UZ
Email enquiries@companies-house.gov.uk
Enquiries (UK) 0303 1234 500
International +44 303 1234 500

The Cardiff office is open 24 hours a day for the receipt of documents Contact Centre lines are open between 8.30am to 6pm (Monday to Friday) 

Unlike recent Locky spam runs, this TrickBot run has gone to a lot of effort to look authentic.

The sender is either noreply@companies-house.me.uk or noreply@companieshouses.co.uk - both those domains have actually been registered by the spammers with fake WHOIS details:

    Registrant:
        Camell Williams

    Registrant type:
        Unknown

    Registrant's address:
        550 HOLTS LAKE CT STE 101
        Suite 101
        Apopka
        Florida
        32703
        United States

Both those domains are close to the genuine one of companieshouse.gov.uk and because the email is digitally signed it might get past spam filters where normal botnet-sent spam wouldn't.

All the emails that I have seen have been sent via servers at 172.99.84.190 and 172.99.88.226 (a Rackspace customer apparently called OnMetal v2 IAD PROD). I recommend that you block email traffic from those IPs.

Attached is a Word document Complaint.doc  (MD5 21AEA31907D50EE6F894B15A8939A48F) [VT 7/55] which according to this Hybrid Analysis downloads a binary from:

futuras.com/img/dododocdoc.exe

This is saved as sweezy.exe and has a detection rate of 7/57. At present that download location is down, probably due to exceeding bandwidth quota.

The Hybrid Analysis identifies several C2s which overlap with this TrickBot run from yesterday:

78.47.139.102 (Unknown customer of Hetzner, Germany)
91.219.28.58 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
91.219.28.77 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
193.9.28.24 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
193.107.111.164 (PP "Kremen Alliance", Ukraine)
193.124.177.117 (MAROSNET, Russia)

The uadomen.com IP ranges (as discussed yesterday) are a sea of badness and I recommend you block traffic to them.

Recommended blocklist:
78.47.139.96/28
91.219.28.0/22
193.9.28.0/24
193.107.111.164
193.124.177.117

Malware spam: "New Fax Message" / administrator@local-fax.com leads to TrickBot

This fake fax leads to TrickBot which appears to be similar to the Dyre banking trojan that we saw a lot of last year..

From:    Administrator [administrator@local-fax.com]
To:    annie@[redacted]
Date:    1 November 2016 at 13:28
Subject:    New Fax Message
Signed by:    local-fax.com

Confidential Fax
Date: 01/11/2016
Recipient: annie@[redacted]
From: +443021881211
Attn:
Important document: For internal use only
The documents are ready. Check attached file for more information.

[THIS IS AN AUTOMATED MESSAGE - PLEASE DO NOT REPLY DIRECTLY TO THIS EMAIL]

Confidentiality Notice: The information contained in this message may be confidential and legally privileged. It is intended only for use of the individual named. If you are not the intended recipient, you are hereby notified that the disclosure, copying, distribution, or taking of any action in regards to the contents of this fax - except its direct delivery to the intended recipient - is strictly prohibited. If you have received this fax in error, please notify the sender immediately and destroy this cover sheet along with its contents, and delete from your system, if applicable.

Attached is a Word document (in this case Internal_Fax.doc) which has a pretty low detection rate at VirusTotal of 5/54. Both the Malwr report and Hybrid Analysis give some clues as to what is going on, but in fact the Malwr report comes out with a binary download location of:

www.tessaban.com/img/safafaasfasdddd.exe

This is a hacked legitimate website. Downloading that file manually and resubmitting it gives two rather more interesting Malwr and Hybrid Analysis reports give the following suspect traffic:

91.219.28.77 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
193.9.28.24 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
37.1.209.51 (3NT Solutions LLP, UK)
138.201.44.28 (Philip Diver, Australia / Hetzner, Germany)
23.23.107.79 (Amazon EC2, US)

I can match all those IPs except the last to this ThreatGeek report, those IPs are a mix of what looks like dynamic IPs for hacked home users and static ones (highlighted):

5.12.28.0 (RCS & RDS Residential, Romania)
27.208.131.97 (China Unicom, China)
36.37.176.6 (VietTel, Cambodia)
37.1.209.51 (3NT Solutions LLP, UK)
37.109.52.75 (Cyfrowy Polsat, Poland)
46.22.211.34 (Inferno Solutions aka 3NT Solutions LLP, UK)
68.179.234.69 (ECTISP, US)
91.219.28.77 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
91.219.28.103 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)
104.250.138.194 (Sean Sweeney, US / Gorillaservers, US)
138.201.44.28 (Philip Diver, Australia / Hetzner, Germany)
188.116.23.98 (NEPHAX, Poland)
188.138.1.53 (PlusServer, Germany)
193.9.28.24 (FLP Kochenov Aleksej Vladislavovich aka uadomen.com, Ukraine)

3NT Solutions (aka Inferno Solutions / inferno.name) are very, very bad news and I would recommend blocking any IPs you can find for this outfit. FLP Kochenov Aleksej Vladislavovich aka uadomen.com has appeared here so many times [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] that really I have to categorise that as an Evil Network too.

If we excise the domestic IPs and blackhole the 3NT / Inferno / uadomen.com ranges we get a recommended blocklist of:

37.1.208.0/21
46.22.211.0/24
91.219.28.0/22
104.250.138.192/27
138.201.44.28
188.116.23.98
188.138.1.53
193.9.28.0/24

However, there's more to this too. The original email message is actually signed by local-fax.com and it turns out that this domain was created just today with anonymous registration details. The sending IP was 104.130.246.8 (Rackspace, US) and it also turns out that this is widely blacklisted and is probably worth blocking.

All the samples I have seen show a consistent MD5 of e6d2863e97523d2f0e398545989666e4 for the attachment, and all the recipients I have seen begin with the letter "a" curiously enough..