More Fake DHL Invoices Delivering Remcos RAT Via Office XML Files

More Fake DHL Invoices Delivering Remcos RAT Via Office XML Files

An old favourite lure with this email with the subject of “DHL Shipping of Original invoice B/L dated 26/10/2018” pretending to come from DHL EXPRESS – < noreply@dhl.com > with a malicious word doc attachment delivers Remcos RAT

The idea of Fake DHL invoices or delivery notes is nothing new. What is different about this campaign is the way the criminals are using non standard Office XML files with base 64 encoded sections containing the macros instead of proper office ( word) docs. These still open in Microsoft Office and will run. They still open in Protected view mode, so a victim needs to click through several times to enable editing, then allow macros, in order to actually be infected.
Normal XML files are readable by humans as well as machines are are basically a text file. These are very different and use lots of separate base64 encoded sections, that need individually extracting & then decoding. ( there is probably a tool somewhere that will do it automatically, but I haven’t found it yet )

We saw the Emotet gang using this type of XML files about a week ago for a few days, but they soon switched back to “proper” word docs.

Fake DHL XML word doc

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

DHL has not been hacked or had their email or other servers compromised. They are not sending the emails to you. They are just innocent victims in exactly the same way as every recipient of these emails.

The email looks like:
From: DHL EXPRESS – <noreply@dhl.com>
Date: Fri 26/10/2021 00:25
Subject: DHL Shipping of Original invoice B/L dated 26/10/2021
Attachment: Dhl Shipping Documents.doc

Body Content:

DHL Shipment Notification
Shipment Successfully Delivered
The following 1 piece(s) have been sent via DHL ,
2018-10-26 on Shipment Number :4920026193;
.Your parcel has-been Delivered.At the request of The Account Holder this notice informs you that the status of the shipment Is Now Complete.
If you wish to view shipment details ;

Screenshot:

fake DHL email

There is also a link in the email but the site is down http://sharedhostingforposty.com/PurchaseOrder.php
Dhl Shipping Documents.doc Current Virus total detections: Anyrun App |

This malware downloads from https://e.coka.la/GRVzbl.jpg Which is a renamed .exe file ( VirusTotal) [2]
One thing to note is Anyrun did not display the full download url in its network section although it did retrieve the Remcos Rat payload. I had to manually decode the 64 bit powershell script to get the download URL.
Update: I have been informed that this is because I didn’t the MITM interception setting so Anyrun can read SSL traffic. THIS updated run shows the traffic

Email Headers:

IP Hostname City Region Country Organisation
162.144.127.137  server.instrumentaltiphive.com Provo Utah US AS46606 Unified Layer
74.208.182.170  Wayne Pennsylvania US AS8560 1&1 Internet SE

 

Received: from server.instrumentaltiphive.com ([162.144.127.137]:39416)
	by my email server with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256)
	(Exim 4.91)
	(envelope-from <veronique.piotelat@orange.fr>)
	id 1gSTZM-0001z7-0V
	for security@myonlinesecurity.co.uk; Thu, 29 Nov 2018 21:09:57 +0000
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
	d=instrumentaltiphive.com; s=default; h=Content-Type:MIME-Version:Message-ID:
	Date:Subject:To:From:Reply-To:Sender:Cc:Content-Transfer-Encoding:Content-ID:
	Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc
	:Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:
	List-Subscribe:List-Post:List-Owner:List-Archive;
	bh=p1V9xm+T7JSlePW9OX15uDv0dw5Umg1373gx6lItiM4=; b=OaqQErakUkjx7NSQcbBnTaPRUz
	lZ3hVlERM9Khv3wYEtmHE2rHv09Ej8isc9b4PDfdYk/JCczRYdlVa57H+Gbxvf7K+3qXRNhLx0Y1a
	1bq47FAIMkNXlrvobdOCnUZrs8lpyu8T1WDViA6HMh9ZcArzToVUPcD6KMv9xA5NwWYZDG1dSpeit
	f1JyQSxcPVlwt83p3JRr9ixzbQ2AWB9YJgB4L52o51KDKoFAfo90lCsEjiTO6J0nukGmr0ungRQBM
	7cnaDInyBCMHSL/ACoeyw+1zoB4lYdCo7sV/GJgx5fGaoKfMZP7/87mjWkeghL9tJthRic5HEKzzg
	jPMGDvbA==;
Received: from [74.208.182.170] (port=50028 helo=orange.fr)
	by server.instrumentaltiphive.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256)
	(Exim 4.91)
	(envelope-from <veronique.piotelat@orange.fr>)
	id 1gFozd-0006Ew-5A
	for security@myonlinesecurity.co.uk; Thu, 25 Oct 2021 23:24:45 +0000
Reply-To: DHL EXPRESS - <noreply@dhl.com>
From: DHL EXPRESS - <noreply@dhl.com>
To: security@myonlinesecurity.co.uk
Subject: DHL Shipping of Original invoice B/L dated 26/10/2021
Date: 25 Oct 2021 23:24:44 +0000
Message-ID: <20181025232444.DBB58E57900EDFF8@dhl.com>
MIME-Version: 1.0
Content-Type: multipart/mixed;
	boundary="----=_NextPart_000_0012_C260E6DD.ECF647A2"
X-AntiAbuse: This header was added to track abuse, please include it with any abuse report
X-AntiAbuse: Primary Hostname - server.instrumentaltiphive.com
X-AntiAbuse: Original Domain - myonlinesecurity.co.uk
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - orange.fr
X-Get-Message-Sender-Via: server.instrumentaltiphive.com: authenticated_id: d@instrumentaltiphive.com
X-Authenticated-Sender: server.instrumentaltiphive.com: d@instrumentaltiphive.com
X-Source:
X-Source-Args:
X-Source-Dir:

All the alleged senders, companies, names of employees, phone numbers, amounts, reference numbers etc. mentioned in the emails are all innocent and are just picked at 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 other 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.

This email attachment contains what appears to be a genuine word doc or Excel XLS spreadsheet with either a macro script or an embedded OLE object that when run will infect you.

Modern versions of Microsoft office, that is Office 2010, 2013, 2016 and Office 365 should be automatically set to higher security to protect you.

By default protected view is enabled and macros are disabled, UNLESS you or your company have enabled them. If protected view mode is turned off and macros are enabled then opening this malicious word document will infect you, and simply previewing it in windows explorer or your email client might well be enough to infect you. Definitely DO NOT follow the advice they give to enable macros or enable editing to see the content.

Most of these malicious word documents either appear to be totally blank or look something like these images when opened in protected view mode, which should be the default in Office 2010, 2013, 2016 and 365. Some versions pretend to have a digital RSA key and say you need to enable editing and Macros to see the content. Do NOT enable Macros or editing under any circumstances.

What Can Be Infected By This

At this time, these malicious macros only infect windows computers. They do not affect a Mac, IPhone, IPad, Blackberry, Windows phone or Android phone.

The malicious word or excel file can open on any device with an office program installed, and potentially the macro will run on Windows or Mac or any other device with Microsoft Office installed. BUT the downloaded malware that the macro tries to download is windows specific, so will not harm, install or infect any other computer except a windows computer. You will not be infected if you do not have macros enabled in Excel or Word. These Macros do not run in “Office Online” Open Office, Libre Office, Word Perfect or any other office program that can read Word or Excel files.

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. Also please read our post about word macro malware and how to avoid being infected by them.

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. It might be a simple message saying “look at this picture of me I took last night” that appears to come from a friend. It might be a scare ware message that will make you open the attachment to see what you are accused of doing. Frequently it is more targeted at somebody ( small companies etc.) who regularly receive PDF attachments or Word .doc attachments or any other common file that you use every day, for example an invoice addressed to sales@victimcompany.com.

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. Many of us routinely get Word, Excel or PowerPoint attachments in the course of work or from companies that we already have a relationship with.

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. A lot of 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”, an invoice or receipt from some company for a product or service or receive a Word doc or Excel file report that work has supposedly sent you to finish working on at the weekend, 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.

With these malformed infected word, excel and other office documents that normally contain a vba macro virus, the vital thing is do not open any office document direct from your email client or the web. Always save the document to a safe location on your computer, normally your downloads folder or your documents folder and scan it with your antivirus. Many Antiviruses do not natively detect vba macro-viruses in real time protection and you need to enable document or office protection in the settings. Do not rely on your Anti-Virus to immediately detect the malware or malicious content. DO NOT enable editing mode or enable macros

All modern versions of word and other office programs, that is 2010, 2013, 2016 and 365, should open all Microsoft office documents that is word docs, excel files and PowerPoint etc that are downloaded from the web or received in an email automatically in “protected view” that stops any embedded malware or macros from being displayed and running. Make sure protected view is set in all office programs to protect you and your company from these sorts of attacks and do not over ride it to edit the document until you are 100% sure that it is a safe document. If the protected mode bar appears when opening the document DO NOT enable editing mode or enable macros the document will look blank or have a warning message, but will be safe.

Be aware that there are a lot of dodgy word docs spreading that WILL infect you with no action from you if you are still using an out dated or vulnerable version of word. This is a good reason to update your office programs to a recent version and stop using office 2003 and 2007. Many of us have continued to use older versions of word and other office programs, because they are convenient, have the functions and settings we are used to and have never seen a need to update to the latest super-duper version. The risks in using older version are now seriously starting to outweigh the convenience, benefits and cost of keeping an old version going.

I strongly urge you to update your office software to the latest version and stop putting yourself at risk, using old out of date software.

IOC:
Dhl Shipping Documents.doc
MD5: 8d1a978f469bef7c995174ae1ecb0b9d
SHA-1: 62d4a0f065c5edfda20e1e54b85c6351846bcdd7
Download URLs
https://e.coka.la/GRVzbl.jpg 163.172.215.76
MD5: 890f5448a1276ad20f997963174bf1cc
SHA1: 1625aa77ed24ed9d052a0153e1939b5a32b352ed

Derek

Derek