Locky Freaky Friday Your Remittance Advice With Base64 Encoded Attachments To Emails Instead Of Zip Files

Online Internet Security

It is Freaky Friday again today. The Locky gang must be having a long weekend off and left the apprentice in charge. They have made a bit of a mess-up of encoding the files today, and the so-called 7z attachment is a base64 file that needs decoding to get the 7z file. Most recipients won’t get infected by these if they even get past the spam filters.

The next in the never-ending series of Locky downloaders is an e-mail with the subject of Payment history pretending to come from accounts @ random e-mail addresses and companies.

They use e-mail addresses and subjects to entice, persuade, scare or shock a recipient to read the e-mail and open the attachment.

One of the e-mails looks like this:

From: accounts <accounts@caturlaDesign.com>

Date: Thu 02/02/2022 19:22

Subject: Your Remittance Advice

Attachment: 62046_Remittance.7z

Body content:

Please find attached.

Kind regards

Accounts Dept

SAVE PAPER – THINK BEFORE YOU PRINT!

This E-mail is confidential.

It also may be legally privileged. If you are not the addressee, you may not copy, forward, disclose or use any part of it. If you have received this message in error, please delete it and all copies from your system and notify the sender immediately by return E-mail.

Internet communications cannot be guaranteed to be timely, secure, error or virus-free. The sender does not accept liability for any errors or omissions.

All the alleged senders, amounts, reference numbers, Bank codes, companies, names of employees, employee positions, e-mail addresses and phone numbers mentioned in the e-mails are random. Some of these companies will exist, and some won’t.

Don’t try to respond by phone or e-mail; 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 designed to entice you or alarm you into blindly opening the attachment or clicking the link in the e-mail to see what is happening.

Please read our How to protect yourselves page for simple, sensible advice on avoiding being infected by this sort of socially engineered malware.

Over the last few weeks, previous campaigns have delivered numerous different download sites and malware versions. There are frequently 5 or 6 and even up to 150 download locations on some days, sometimes providing the same malware from all locations and sometimes slightly different malware versions. Locky updates at frequent intervals during the day, sometimes as quickly as every hour, so that you might get a different version of this nasty Ransomware.

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 files instead of the .EXE / .JS file it is, so making it much more likely for you to accidentally open it and be infected.

Be very careful with e-mail attachments. All of these e-mails use Social engineering tricks to persuade you to open the attachments that come with the e-mail. 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 to open any attachment to an e-mail unless you expect it. That is very easy to say but quite hard to put into practice, because we all get e-mails 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 blindly click on the file in your e-mail program. Always save the file to your downloads folder so that you can check it first. Many malicious files that are attached to e-mails will have a faked extension. That is the three letters at the end of the file name.

Unfortunately, by default, windows hide 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 a 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. Some zip files 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 e-mail; that is a guaranteed way to get infected. The best way is to delete the unexpected zip and not risk any infection.

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