Following on from Last Friday, it is looking like Windstream, Zimbra & Synacor still have a problem with accounts being compromised and mass malspam being sent. Generally speaking the majority of ISPs are pretty good with blocking outgoing spam & malware emails. They generally restrict the numbers of emails sent per hour / day for each account and the limit is normally very low, in the 10’s or low 100’s, unless you have a business account where the sending limits are much higher. That is why we normally see the majority of malspam coming from fraudulently set up, or compromised accounts on webhosting servers who have much higher sending limits by default, often in the several hundred, thousands or in many cases tens of thousands.
Over recent years various criminals have found security holes in many mailing services to send their malicious malspam. We saw campaigns abusing Sendgrid, Mailchimp, Mailgun and just about every other similar service over recent years. I hope that this current ( so far) lowish volume malspam campaign is using compromised individual email addresses and accounts on Windstream, rather than a compromise or security hole on Windstream/ Synacor / Zimbra
It is highly likely that it is an individual customer of Windstream that has been compromised, rather than the entire system, but the whole idea of a company outsourcing mailing services to a 3rd party like Zimbra / Synacor is their filtering systems that is supposed to detect & block malware, spam and other malicious content
Windstream are a major US ISP / Telecoms company / entertainment services provider all over the USA with hundreds of thousands if not millions of customers, both domestic and commercial.
The email is nothing special but due to passing all authentication stands a higher change of passing through spam and malware filters and being delivered to recipients. This email also attempts to bypass malware and content filters by having the malicious content inside a zip file which is inside another zip file.
As you can see from the email headers the emails actually come via an mailing service syn-alias.com owned by Synacor using Zimbra mailing system which is used by numerous large corporations worldwide for mass mailings and mail services.
I could not get this to run in a Windows 7 sandbox on Anyrun only a windows 10 sandbox / VM and can only get it to run when using a USA system.
This appears to be Orion Keylogger, which although has been around for several years was fairly recently “hacked” and released to the skiddie community.
The delivery / checkin system for this is quite difficult for me to follow.
This drops a small .exe file to %usertemp% folder VirusTotal | This file appears to do the connecting to the intermediate C2 which is behind cloudflare and abusing the puush.me image hosting service. http://puu.sh/jMSLc.txt (this gives a base 64 encoded ID code ) and tries to connect to https://puu.sh/y0rxd.dll which gives a 404. From what I can see unless you get the ID code in the text file, nothing happens.
The keylogger connects to 18.104.22.168 mail.fajr.com hosted on gator3241.hostgator.com using the user name of email@example.com which most likely is a compromised user.
It looks like Puush.me also need to clean up their act & stop non image files being hosted / shared / distributed on or via their system. They were set up to be a screenshot or other small image sharing service to make it easy to share the same image on multiple social media services.
You can now submit suspicious sites, emails and files via our Submissions system
hofbraurestaurant does exist in Georgia USA and it is extremely likely that they don’t know their email address is compromised and being used in this Malspam campaign.
One of the emails looks like:
From: Sales <firstname.lastname@example.org>
Date: Sun 09/06/2019 22:10
Subject: Order Inquiry
Attachment: Order1002 Quotation.zip
I need quote for the following product list attached.
Send your payment terms, best price, FOB and delivery time asap.
No.2 Asiatic floor – 54850
Phone: 008536544840, 36545346-7
|22.214.171.124||mail.windstream.syn-alias.com||Buffalo||New York||US||AS36271 Synacor, Inc.|
|126.96.36.199||no-mans-land.m247.com||Miami||Florida||US||AS9009 M247 Ltd|
Note: Only the final IP address outside of your network in the Received: fields can be trusted as others can be spoofed
Received: from mail.windstream.syn-alias.com ([188.8.131.52]:60589 helo=mail.windstream.net) by my mail server with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92) (envelope-from <email@example.com>) id 1ha55v-0002w6-E7 for firstname.lastname@example.org; Sun, 09 Jun 2019 22:11:16 +0100 DKIM-Signature: v=1; a=rsa-sha1; d=windstream.net; s=20180222; c=relaxed/simple; q=dns/txt; email@example.com; t=1560114666; h=From:Subject:Date:To:MIME-Version:Content-Type; bh=DgDUYe4W5vuQCfC3JouF+Vdlauw=; b=jFlRn86shQkkoEqajUW5Xv/dtMlHGYiidKZetqQa8H/vB0fNVvYoTv+b8ZGySxiZ ThT3oqU4NnVqnYrWjjAV0Ixp4nEeLv1jFLJmKJAa376NDcELeQfWEQdIysGgLGjb lCm/T2D0HGC7ihZ3khAqmYuTLVV720aJCm990oeRQB9fBlJLSObX8H4bjiVmXWUp U430LP5068dgxVpL4V/tJp8wCiWDmx5qxVbrneFfmk5brJZ8K4Hj/gR+n8bfNdcG TLUNjW5iK0PtRQN5L0c0GxOloajRxSR1Vjg5HLdUbRnMZcARcZkiIYgDiDBYcJC9 KXh4IOzSoZbfF8qchx91Vg==; X_CMAE_Category: , , X-CNFS-Analysis: v=2.2 cv=TNQHcBta c=1 sm=1 tr=0 a=u0k4CDdXBZVbuoB8PalGkg==:117 a=u0k4CDdXBZVbuoB8PalGkg==:17 a=KGjhK52YXX0A:10 a=dq6fvYVFJ5YA:10 a=vIygHoJDk_sA:10 a=KXl77lDgDEgIEtoqJYcA:9 a=w13Q1pGNA67F4NIj6xgA:9 a=mxjOGqPAYyrhmwtx:21 a=tx6BEGTqIlMYFXPh:21 a=wPNLvfGTeEIA:10 a=8lNNXYnAuwkA:10 a=y9ne-TmfRe0A:10 a=VjgvUEuDJtQA:10 a=L8gXwi5ktC4C0IRcuG4A:9 a=IKIoO-ieCDEA:10 a=Yy2xoct6d_2ZlxTvqP-Z:22 a=y3gxJGGnbrtUV2GOxcvc:22 X-CM-Score: 0 X-Scanned-by: Cloudmark Authority Engine X-Authed-Username: aG9mYnJhdXJlc3RhdXJhbnRAd2luZHN0cmVhbS5uZXQ= Authentication-Results: smtp02.aqua.bos.sync.lan firstname.lastname@example.org; auth=pass (LOGIN) Received: from [184.108.40.206] ([220.127.116.11:59705] helo=[10.8.0.9]) by mail.windstream.net (envelope-from <email@example.com>) (ecelerity 18.104.22.168547 r(Core:22.214.171.124)) with ESMTPSA (cipher=DHE-RSA-AES256-SHA) id 45/08-30569-9D57DFC5; Sun, 09 Jun 2019 17:11:02 -0400 Content-Type: multipart/mixed; boundary="===============0375756087==" Message-ID: <45.08.30569.9D57DFC5@smtp02.aqua.bos.sync.lan> MIME-Version: 1.0 Subject: Order Inquiry To: Recipients <firstname.lastname@example.org> From: "Sales" <email@example.com> Date: Sun, 09 Jun 2019 14:10:29 -0700
These malicious attachments normally have a password stealing component, with the aim of stealing your bank, PayPal or other financial details along with your email or FTP ( web space) log in credentials. Many of them are also designed to specifically steal your Facebook and other social network log in details. A very high proportion are Ransomware versions that encrypt your files and demand money ( about £350/$400) to recover the files.All the alleged senders, amounts, reference numbers, Bank codes, companies, names of employees, employee positions, email addresses and phone numbers mentioned in the emails are all random. Some of these companies will exist and some won’t. Don’t try to respond by phone or email, all you will do is end up with an innocent person or company who have had their details spoofed and picked at random from a long list that the bad guys have previously found. The bad guys choose companies, Government departments and organisations with subjects that are designed to entice you or alarm you into blindly opening the attachment or clicking the link in the email to see what is happening.
Please read our How to protect yourselves page for simple, sensible advice on how to avoid being infected by this sort of socially engineered malware.
This is another one of the files that unless you have “show known file extensions enabled“, can easily be mistaken for a genuine DOC / PDF / JPG or other common file instead of the .EXE / .JS file it really is, so making it much more likely for you to accidentally open it and be infected.
Be very careful with email attachments. All of these emails use Social engineering tricks to persuade you to open the attachments that come with the email. Whether it is a message saying “look at this picture of me I took last night” and it appears to come from a friend or is more targeted at somebody who regularly is likely to receive PDF attachments or Word .doc attachments or any other common file that you use every day.
The basic rule is NEVER open any attachment to an email, unless you are expecting it. Now that is very easy to say but quite hard to put into practice, because we all get emails with files attached to them. Our friends and family love to send us pictures of them doing silly things, or even cute pictures of the children or pets.
Never just blindly click on the file in your email program. Always save the file to your downloads folder, so you can check it first. Many malicious files that are attached to emails will have a faked extension. That is the 3 letters at the end of the file name. Unfortunately windows by default hides the file extensions so you need to Set your folder options to “show known file types. Then when you unzip the zip file that is supposed to contain the pictures of “Sally’s dog catching a ball” or a report in word document format that work has supposedly sent you to finish working on at the weekend, or an invoice or order confirmation from some company, you can easily see if it is a picture or document & not a malicious program.
If you see JS or .EXE or .COM or .PIF or .SCR or .HTA .vbs, .wsf , .jse .jar at the end of the file name DO NOT click on it or try to open it, it will infect you.
While the malicious program is inside the zip file, it cannot harm you or automatically run. When it is just sitting unzipped in your downloads folder it won’t infect you, provided you don’t click it to run it. Just delete the zip and any extracted file and everything will be OK. You can always run a scan with your antivirus to be sure. There are some zip files that can be configured by the bad guys to automatically run the malware file when you double click the zip to extract the file. If you right click any suspicious zip file received, and select extract here or extract to folder ( after saving the zip to a folder on the computer) that risk is virtually eliminated. Never attempt to open a zip directly from your email, that is a guaranteed way to get infected. The best way is to just delete the unexpected zip and not risk any infection.
Main object- “Contract PO-ORDER.exe”
Dropped executable file
sha256 C:\Users\admin\AppData\Local\Temp\bfsvc.exe f740df4d3a6c0b378116b48c1ed18a36e82938cf7dcaaba58f0ba8101f3e3531