JavaScript Malware

caution malware

JavaScript malware  is a different way of spreading malware. We have been seeing a steady increase in a different form of malware spreading. The bad guys are sending javascript files inside a zip or at the end of a link.

We have seen several different email templates for this method ranging from

E-Ticket 7694892 pretending to come from E-Ticket <online@ticket.com>

Resume Bobbie Rocha – JavaScript malware

Order 595775 which contains a simple email reading something like “Good Day!  Find Order 595775 attached  Thank you Jim Olsen” These also come in as fake invoices with random numbers and random names and senders. You normally find the name in body of email matches the name of the alleged sender

I am seeing a low volume but steady stream of these js malwares, detections are not as good as they could be
https://www.virustotal.com/en/file/d5d1c0db6439d57fe0fb9233b9b3b2f309d91baf06963ce5d45b0abfee6cab15/analysis/1430374815/
they aren’t being spammed out on mass like the other bots do and seem to be targeted at small business
All the copies I see come in to proper email addresses and not honeypots or catch all emails
they have all come in to emails that are public on websites for small companies or charities/non profit organisations who are less likely to have  a proper IT support system.
Every copy I have seen so far has had a different # which is making it harder to detect

These particular js files (JavaScript malware) download & install a cryptowall 3.0 malware which will encrypt all your files on the computer and prevent access to them. There is absolutely no fix once you are infected so it is essential to have a full working backup and make sure it is stored off the computer. These cryptowall Trojans are network aware and will encrypt all network disks and external hard discs as well as the computer hard disc.

All the alleged senders, companies, names of employees and phone numbers 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 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.

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

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. 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 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.

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. Most ( if not all) 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” or a report in word document format 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 .EXE or .COM or .PIF or .SCR 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. There are some zip files that 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 email, that is guaranteed way to get infected. The best way is to just delete the unexpected zip and not risk any infection.