This is a weird one and I can’t determine what the final payload does via running the files in an online sandbox. I really don’t know if the bad actor has messed up or whether it is an anti-vm or anti-sandbox protection on it. The .z attachment on the emails is not correct and the actual attachment is a .iso file that has been renamed or mistakenly given a .z extension.

I received 2 different copies of this email with the same payload and email content but coming from different email addresses and domains both on the same server with slightly different subjects.

Trying to extract via winzip fails, unless I rename to .iso, but I can extract using universal extractor or 7zip & winrar on the sandbox, which seem to use magic file headers rather than rely on the stated file extension. Anyway once we manage to extract the content we get an encrypted javascript file which contains an embedded .exe which is eventually extracted and should run. However I can’t get anything much happen on any sandbox. It also drops a vbs file that is supposed to start the file.

My gut feeling is this is probably Hawkeye keylogger, that just isn’t working properly. It either sleeps for longer than the 15 minutes that I can run on a sandbox or it is broken.

Update: With a lot of help from many other researchers on Twitter, there appears to be a consensus that this is a new bitcoin currency stealer. One researcher found a bitcoin address in the file. The same researcher and another researcher concurrently found C:\Users\USER\Desktop\BitPing-master\BitPing\obj\Release\BitPing.pdb which after a bit of digging suggests that this uses (abuses) https://github.com/ParsingTeam/BitPing which is described as BitPing A Simple Bitcoin Address Changer From Clipboard.

What I believe happens, is that the malware stealer file only triggers when you are on one of the bitcoin wallet sites or when you copy or paste in your bitcoin address. This misuses the BitPing “tool” to replace your bitcoin address with the criminal’s one so any payments to your bitcoin addresss instead go to his account. What the criminal is hoping is that you install the malware that will only trigger when you send somebody else your bitcoin address to pay you. That is replaced by the criminal’s address and he gets the money instead of you.

You can now submit suspicious sites, emails and files via our Submissions system

25301PMISTR.z ( VirusTotal) : Extracts to: 25301PMISTR.jse Current Virus total detections: Payload Security | Anyrun | which extracted / dropped rewjavaef.exe ( virustotal) Which is quite well detected generically but not as any specific threat.
One of the emails looks like:
From: Global INC <[email protected]>
Date: Tue 12/03/2021 01:03
Subject: FW: Review Your New Bitcoin International Investment Update 2021
Attachment: 25301PMISTR.z

Body Content:

Hi,
Please find attached file.
Regards,
Evan.
FINRA
1735 K Street, NW
Washington DC, 20006
(301) 590-6700

Screenshot:

Fake Bitcoin email scam delivering malware

Fake Bitcoin email scam delivering malware

Email Headers:

IP Hostname City Region Country Organisation
80.85.154.145  dph2.logistic.pserver.ru RU AS44493 Chelyabinsk-Signal LLC

 

Received: from dph2.logistic.pserver.ru ([80.85.154.145]:57400 helo=globaleuro.net)
	by my email serverwith esmtp (Exim 4.91)
	(envelope-from <[email protected]>)
	id 1h3XH3-0008Rz-F5
	for [email protected]; Tue, 12 Mar 2021 02:36:14 +0000
Reply-To: Global INC<[email protected]>
From: Global INC <[email protected]>
To: [email protected]
Subject: FW: Review  BTC
Date: 11 Mar 2021 19:36:14 -0700
Message-ID: <[email protected]>
MIME-Version: 1.0
Content-Type: multipart/mixed;
	boundary="----=_NextPart_000_0012_B49D9195.8C9C62F0"
Received: from dph2.logistic.pserver.ru ([80.85.154.145]:56988 helo=intellie-international.com)
	by my email server with esmtp (Exim 4.91)
	(envelope-from <[email protected]>)
	id 1h3Von-00049E-AF
	for [email protected]; Tue, 12 Mar 2021 01:02:58 +0000
Reply-To: Global INC<[email protected]>
From: Global INC <[email protected]>
To: [email protected]
Subject: FW: Review  Your New Bitcoin International  Investment Update 2021
Date: 11 Mar 2021 18:02:57 -0700
Message-ID: <[email protected]>
MIME-Version: 1.0
Content-Type: multipart/mixed;
	boundary="----=_NextPart_000_0012_B855F26B.9A2A7FC3"

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.

IOC:
Main object- “25301PMISTR.z”
sha256 8e25fc4c9d8f3fad6b793e728cb1d96542b42d04f0bdbbae6ab4e43d2611b428
sha1 7e01b4a8d673d6e372b0525dd735f28d51db0027
md5 1ae9308f9aa6e3e374bd7fdd37a2b320
25301PMISTR.jse
SHA-256 0edefa10bdf4fb001bea9e5439db47e406d20e622e66a0339f5be1ce97ba2417
MD5 d4555595b6c6ff65b1fc8b3acc277660
SHA-1 d3144f7c1bdefe44ec54403401c0fa5340e33ad6
Dropped executable file
sha256 C:\Users\admin\AppData\Local\Temp\rewjavaef.exe 966bf2f4e72e7dd86e3951d8e78ed3950b83f0a5053e8a2e62016512042c9f35
MD5 79f73819f3da9968918b5fa257a40744
SHA-1 873de2e159868b977495559de912b34c6e892b90