Home Malware Beware Emails With Subject Lines Containing Numbers, Letters and Image File Extensions

Beware Emails With Subject Lines Containing Numbers, Letters and Image File Extensions

by Brett M. Christensen

Emails with no body text and subject lines containing a string of letters and numbers and image file extensions such as .jpg or .tiff are currently hitting inboxes. The emails contain attachments with the same names and image file extensions that are featured in the subject lines.

Brief Analysis:
The attachments contain malicious JavaScript files that, if opened, can download and install Locky ransomware. Once installed, Locky encrypts the files on your computer and then demands that you pay a fee to receive a decryption key.


Locky Image Malware Emails

Detailed Analysis:
Sometimes, very simple social engineering tricks can be quite effective. In this malware campaign, the malicious emails have no content in the body, but are designed to give the impression that the attachment that comes with the emails contains a harmless image file.

The subject lines of the emails often feature the letters CCE along with a  string of numbers followed by an image file extension such as .jpg, .gif, or .tiff.  Over the last few days, we’ve received emails with the subject lines  ‘CCE29032016_00084.tiff’, ‘CCE29032016_00021.gif’, ‘CCE29032016_00026.jpg’, and dozens of others. The emails usually include the notice ‘Sent from my iPhone’ in the footer.

The emails have attachments with the same names and image file extensions as shown in the subject lines. However, the attachments actually have double extensions such as .jpg.zip or .tiff.rar. Windows users who have file extensions hidden will only see  ‘.jpg’ or ‘.tiff’ and may therefore assume that the attachments just contain images.

If you do get tricked by this simple ruse and open the attachment, you will find that it is a compressed file that harbours a malicious JavaScript (.js) file. If you then proceed to click this .js file, the JavaScript will connect to a remote server and download and install Locky ransomware. Once installed, this malware will encrypt the files on your computer and rename them with the file extension ‘.locky’. A popup window will then inform you that you must pay a ransom to get the decryption key to unlock your files.

Unfortunately, there is no easy way to get rid of this malware and recover your files.  If you have recent, off-computer backups, you should be able to recover your files from the backups. Without backups, however, it may be impossible to unlock your files unless you pay the ransom demanded by the criminals. If you do pay, you MAY receive the promised decryption key. However, given that you will be dealing with anonymous criminals, there is certainly no guarantee that you will ever receive the key.

Note that some versions of these emails may omit the file extension from the subject line and just have the letters and numbers. And, the letters, numbers, and file extensions may vary considerably in different versions.  There are also many other Locky ransomware emails currently being distributed. Check the reference list below for reports on other Locky campaigns.

Locky Ransome Ware

Last updated: March 31, 2016
First published: March 31, 2016
By Brett M. Christensen
About Hoax-Slayer

‘Payment Declined’ Emails Contain Locky Ransomware
Bogus ‘Payment Accepted’ Email Carries Locky Ransomware
Fake ‘Order Status’ Emails Contain Locky Malware
‘Received Documents From Your Bank’ Emails Contain Locky Ransomware
“Locky” ransomware – what you need to know
How to show or hide file extensions in Windows


Importance Notice

After considerable thought and with an ache in my heart, I have decided that the time has come to close down the Hoax-Slayer website.

These days, the site does not generate enough revenue to cover expenses, and I do not have the financial resources to sustain it going forward.

Moreover, I now work long hours in a full-time and physically taxing job, so maintaining and managing the website and publishing new material has become difficult for me.

And finally, after 18 years of writing about scams and hoaxes, I feel that it is time for me to take my fingers off the keyboard and focus on other projects and pastimes.

When I first started Hoax-Slayer, I never dreamed that I would still be working on the project all these years later or that it would become such an important part of my life. It's been a fantastic and engaging experience and one that I will always treasure.

I hope that my work over the years has helped to make the Internet a little safer and thwarted the activities of at least a few scammers and malicious pranksters.

A Big Thank You

I would also like to thank all of those wonderful people who have supported the project by sharing information from the site, contributing examples of scams and hoaxes, offering suggestions, donating funds, or helping behind the scenes.

I would especially like to thank David White for his tireless contribution to the Hoax-Slayer Facebook Page over many years. David's support has been invaluable, and I can not thank him enough.

Closing Date

Hoax-Slayer will still be around for a few weeks while I wind things down. The site will go offline on May 31, 2021. While I will not be publishing any new posts, you can still access existing material on the site until the date of closure.

Thank you, one and all!

Brett Christensen,