Overnight we have seen another mass Japanese Malspam campaign with a change to the malware downloaders delivering some sort of malware that is being detected on VirusTotal as a ransomware. I am not certain that is a correct detection. This gang traditionally deliver Ursnif / Gozi banking Trojan and it has been very frequently mis-identified by several antiviruses as a ransomware. However I am open to it being almost any malware with recent changes we have been seeing.
Update: Kaspersky have replied with an ID of Trojan-Banker.Win32.Shiotob.wiu ( which I have never heard of) but does fit the Ursnif /Gozi pattern more closely than ransomware.
The subject of 2017.6支払依頼書 ( 2017.6 Payment Request Form) pretending to come from random Japanese email addresses with a zip file . Quite unusually for this gang, nearly all all the versions we have received overnight have had the same subject and body content, they normally vary them. We have seen a couple of different ones still on the invoice theme with a numbered zip attachment
They are using email addresses and subjects that will scare or entice a user to read the email and open the attachment. A very high proportion are being targeted at small and medium size businesses, with the hope of getting a better response than they do from consumers.
Remember many email clients, especially on a mobile phone or tablet, only show the Name in the From: and not the bit in <domain.com >. That is why these scams and phishes work so well.
The email looks like:
From: [email protected]
Date: Tue 27/06/2021 04:41
Subject: 2017.6支払依頼書 ( 2017.6 Payment Request Form)
Attachment: 2017.6支払依頼書.zip ( 2017.6 Payment request form.zip)
Body Content:
お疲れ様です。
請求書金額を入力した支払依頼書を添付いたしました。
ご確認後、印刷し原本のご郵送をお願い致します。
宜しくお願いたします。
Translates to:
Is cheers for good work.
We have attached a payment request with the invoice amount entered.
After confirming, please print and mail the original.
Thank you.
Screenshot:
2017.6支払依頼書.zip Extracts to DOC0978043-2017.6.doc.js Current Virus total detections: Payload Security shows downloads from www.feuerwehr-brieselang.de/media/vector.tui and matied.com/gerv.gun but didn’t retrieve the payload. Manually getting it ( VirusTotal ) ( Payload Security ) Lots of AV on Virus Total describe these as Locky or some other ransomware. I am not certain that I agree with that. Normally this gang deliver Ursnif/Gozi Banking Trojan not a ransomware. It has been relatively common recently for a lot of antiviruses to mis-identify the ursnif payload as ransomware
2017-57787733-885.zip extracts to 2017-547805549-231.pdf.js Current Virus total detections: Payload Security contacts same sites & downloads same malware
Almost all of these were quarantined by ClamAv on my mailserver due to double extensions in file name ( for some reason 2 got caught as spam but not identified as virus)
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.
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 [email protected].
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.