UnicMinds Cyber Security Course: Can you trust .jpg files?

Most people get spooked when they’ve to download .exe files or .scr files. But, people generally trust .jpg files as they think they’re just images and assume they’re harmless. But, in our Ethical Hacking course we teach students on why .jpg files shouldn’t be trusted and how right to left override attacks (renaming) can hide an exe file in plain sight.

Right to Left Override Attacks - hiding exe files in plain sight

Hackers popularly use this method to hide trojan malware in the form of jpg files. Here’s how:

You use the RLO character and change the name of the file to bluegpj.exe (you can copy the character from ( Link: https://unicode-explorer.com/c/202E)

Insert the Unicode RLO character after the word blue -> blue gpj.exe

The filename will look like: blueexe.jpg (But the actual file name typed is bluegpj.exe)

But the file name still has “exe” in it and it might look suspicious

So, I will replace blue with a word that ends with exe

Replace “blue” with “ann”

The filename will look like “annexe.jpg”

Type “Ann” and then copy/paste the Unicode character and then continue typing “gpj.exe”.

The filename looks like “Annexe.jpg”, but the actual file name is “Anngpj.exe”. This is an exe file that looks like a harmless .jpg file.

Now you have the trojan filename ready, somebody will think it is a jpg picture, but it is an exe file that will run a program when double clicked.

It is important to be aware of these methods so that we are alert and don’t fall prey to such attacks. Always be careful when downloading files from unknown websites or untrusted publishers. Here’s a list of extensions that you’ve to be cautious of downloading.

As responsible individuals, we’ve to try earnestly to do better in this world and not by wrong means. In our courses, we help students learn the various technical aspects in the most genuine way from our heart in every effort. We believe if you do earnest work from your heart, things will fall in place, and that there is no real replacement for “hard work” for anyone.

Hope this is useful, thank you.