Article by Bjorn Leenen.
It was just another day at the office. Morning coffee in one hand and in the other my mouse was going through the unread emails in my mailbox. Then, there it was. I received an email with a purchase order from a certain Heikal Mahsir, with an attachment that is supposed to be an order they wanted to place with me. Normally I wouldn't open these attachments and they would go straight into the trash, but just to humour myself I opened purchase.pdf.
Up to this point my local scanner did not warn me and this email also made it through my spam filter. Apparently this is not a harmful attachment. Opening the PDF showed me the following:
The CLICK link told my browser to go to: http://www.mesaimeerclub.com/templates/invest/just (this page does not work anymore but please, for safety reasons stay away from it).
The look and feel of the site resembled a Gmail signup page so an unsuspecting end-user could be easily duped into filling out his email address and password to log in to Gmail or Google Drive thinking in so doing he would be able to open the purchase-order.
After I logged in with a dummy Gmail account I had set up previously (with no real data in it) I saw nothing happen. After a few minutes I closed the browser screen because up to that moment nothing had happened and it looked harmless.
Then it hit me: why not try to log back into the dummy Gmail account and see what happens there. But I couldn't anymore! The password was changed and even the recovery option didn't work anymore. This would have been a disaster scenario if I associated all my online shopping, my social networks, even my official e-mail accounts with this account (which is very well possible today).
Thankfully that wasn't the case but there are still some takeaways from this.
We have to acknowledge the vast volume of emails we receive per day, ranging from social network updates, internal updates, orders, questions from known and unknown people etc. Depending on the department you are in, they are either related to what you do all day long, or in this case, not, since I work in the engineering department and have nothing to do with sales. This makes it very difficult and cumbersome for end-users to avoid falling victim to a phishing attack if they are not properly trained. The content of some phishing emails can be difficult to separate from what is valid and what is not. The reader is very easily tricked into opening and executing the malicious code. In this example there were barely any grammatical errors and the malicious website looked legit.
There are so many different attempts to get you to follow links, open the scripts, or go to malicious websites try to take over what is yours. Why? Because your data is valuable http://www.gfi.com/blog/how-much-does-your-stolen-data-go-for/ – not to mention the proliferation ransomware which encrypts your information, or in this case locks you out of your account, and demands money for you to regain access.
Ransomware creators are getting cleverer and more ruthless as time goes by, and always finding new ways to part you with your money. The first releases of ransomware in 2014 asked for around 0.5 Bitcoins (USD 325) to decrypt the data, but we have come across new variants that will request up to 8 Bitcoins within 24 hours and double that after time has run out. Ransomware doesn't just target end users but also businesses and even IT Administrators, because of their possible elevated rights within the infrastructure.
Instead of trying to cover these rules again, I'd like to hand over a few lessons that can be passed on to ALL the users within the organization. As an IT administrator you're probably already well armed against these kind of attacks. but A regular end user may not have a clue.
This is why a simple approach needs to be taken so remind your users:
- If an email attachment from someone you know but who normally doesn't send those kind of attachments, call the sender and ask if they did indeed send something over. Do not open the attachment immediately.
- If you received any invoices, purchase orders, special delivery notes but this is not your line of work, check if the sender is known and ask if they sent something over. If the sender is unknown or looks suspicious you're better off deleting the email. If you receive a document from a colleague (even the boss!) and there is a desperate note in it to open the file, call your colleague and ask if they did indeed send something over. Even the boss shouldn't mind, you may have just saved him an encrypted server with that call.
- If ANY attachment is asking for opening a link, because scripting is disabled, or editing is disabled, do not enable this! If data looks scrambled, there's a 99% chance it's a decoy to encrypt all data.
- Do not open private emails on company owned devices and vice versa! Cryptoware targets businesses and you might get infected by opening it on your own machine (and probably the boss will not pay). And opening private emails on company owned devices with encrypted data as a result, might put you in a difficult spot with HR.
- Remember that organisations like Microsoft, energy-suppliers, postal services and many more, will never call you asking you to open a website to restore some setting, open an order, invoice or such things. The scammer is just trying to trick you into giving them access to your machine.
Unfortunately there is not one, easy access formula which will stop all of this from happening. The best we can do is mitigate the risks as best we can using layered security. Bad emails may still pass through and some malicious adverts may still be shown on webpages, and your users, being the last layer of security, need to be prepared and know what can happen if the full blown malicious intent was executed. Finally, it's of paramount importance to have all other measures in place to recover from potential breaches by having a working backup or disaster recovery plan. Know who to call, what to do, how to recover and where to look when things don't go as expected.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.