Emotet is one of the most feared malwares out there

The team behind it has managed to infect a staggering array of targets all around the globe. To say that it is a major threat would be an understatement. Recently the group behind Emotet just upped the ante even further. Researchers have recently discovered that malware is now being distributed via a new channel.

The new channel is a malicious Windows App Installer that appears to be an innocuous Adobe PDF reader. Windows App Installer is a built-in feature of both Windows 10 and 11 and systems can be infected by "tricking" users to click attachments in emails that trigger the App Installer.

Emotet's preferred methodology revolves around a "conversation in progress" approach.  An email is crafted that already has several replies. So at a glance, it appears that the recipient and whoever sent this email have already been conversing about something. The "most recent" reply says some variation of "please see attached" and contains a PDF file.

 

A self-installer is hidden in PDF file

When the recipient clicks the file the built-in App Installer is triggered, and the malware is installed. Note that this completely bypasses most malware and AV software because the recipient is making a conscious decision to open the file in question.

The campaign is amazingly well put together.  The attachment and subsequent prompts appear to be legitimate Adobe Acrobat components right down to sporting an official company icon and a certificate marking it as a trusted application. So, there's no reason for a user to think that there's anything amiss unless they look more closely at the email containing the attachment.

That's exactly what the hackers are counting on.  They know that people are busy and may only give the body of the email a cursory glance before clicking to see what all the fuss was about.

 

My perspective

As ever vigilance and mindfulness are the keys to avoiding these types of shenanigans. Have a discussion with your employees and apprise them of the danger.

 

It's as if the Wicked Witch of the West is saying:

"I'll get you, my pretty, and your little dog too!"

 


By Denis Wilson

Cybersecurity Expert, Small Business Technology Consultant, Managed Services Provider, Managed IT Support

Thanks for reading this post. I always take into mind that your time and attention are precious. And these posts need to be timely, to the point, and short.

For more tips on thriving with small business technology, check out the other blog posts at DWPIA Blogs. You can also find me on LinkedIn, Facebook, and Twitter

I am also a published author and speaker on cloud computing, work-at-home, and cybersecurity. I work extensively with business and professional associations to provide free small business technology education programs.

 

Contact me if you would like me to speak to your association