Fake ISP “Spam Mailout” Notifications Contain Locky Ransomware

Outline:
Email purporting to be from “ISP Support” claims that your ISP has received spam mailouts from your address recently and urges you to open an attached file to view a log of the supposed spam messages.




Brief Analysis:
The email is not a genuine notification from your ISP and the attached .zip file does not contain a log of spam messages as claimed. Instead, the attachment contains a malicious JavaScript file that, if opened, can download and install Locky ransomware on your computer.

Example:
Dear [Name Removed]

We’ve been receiving spam mailout from your address recently.

Contents and logging of such messages are in the attachment.
Please look into it and contact us.

Best Regards,
[Random Name]
ISP Support
Tel.: [Removed]

Attached File: logs_[same text as email greeting].zip





Detailed Analysis:
According to this email, which claims to be from support staff at your Internet Service Provider (ISP), your email address has recently been sending spam mailouts. It claims that the contents of these spam emails are contained in an attached log file. It asks that you look into the issue and then contact your ISP.

However, the email is not from your ISP and the attachment does not contain a log of spam emails. If you open the attached .zip, you will find that it contains a JavaScript (.js) file. If you then open the .js file, a malicious JavaScript can download and install Locky ransomware on your computer.

Once installed, Locky can encrypt all of the important files on your computer and then demand that you pay a ransom to online criminals to receive a decryption key. If you do not have adequate recent backups of your files, recovering from a ransomware attack can be very difficult. Many victims have been forced to pay the criminals to retrieve access to their files. However, given that you are dealing with criminals, there is really no guarantee that you will receive the decryption key, even if you do pay up.

The email uses a greeting derived from the first part of  the recipient’s email address, which will often be the recipient’s name.  This tactic may serve to make the malware email appear more legitimate as it may seem that the message is addressing you by name and is thus likely to be  from a company or person that knows you.

The name of the supposed ISP staff member who sent the email also varies.

If you receive one of these emails, do not click any links or open any attachments that it contains.




Locky Ransomware

Last updated: November 23, 2016
First published: November 23, 2016
By Brett M. Christensen
About Hoax-Slayer

References
REMOVE LOCKY AESIR ITERATION. RESTORE .AESIR FILES
Locky delivered by spoofed ISP you have been sending spam notifications
Fake Airline “Travel Itinerary” Emails Lead To Locky Ransomware