From Threat to Prank: The Top 5 Funniest (and Most Annoying) Trojans in History

Hello everyone at CodeWithBotina! If you've watched our latest YouTube video on Trojans, you already know that these threats can steal bank credentials or even shut down nuclear plants. It is a very serious topic.

However, not all malware creators wanted to destroy the world or steal your money. In the golden ages of the internet (the 90s and 2000s), many programmers built trojans for one single purpose: trolling their friends and driving users crazy.

Today we are taking a break from corporate cybersecurity to have a good laugh. Here is our Top 5 list of trojans created purely to annoy.

5. The CD Tray Poltergeist (SubSeven)

SubSeven was actually a very dangerous Remote Administration Tool (RAT), but it had features that "script kiddies" absolutely loved. One of the most popular was a button that simply opened and closed the victim's CD-ROM tray uncontrollably. Imagine being alone at 3 AM and your computer starts sticking its tongue out at you out of nowhere.

4. The Screen Flipper (FlipScreen)

There is nothing that confuses an average user more than changing their monitor's orientation. This harmless trojan hid in fake executable files, and when opened, it rotated the screen 180 degrees, also inverting the mouse axis (if you moved up, the cursor went down). Fixing it was a hilarious headache.

3. The Drunk Hardware (Drunk Mouse / Drunk Keyboard)

This is a classic office prank. Once installed, this trojan waited for the user to work for a few minutes. Suddenly, the mouse pointer would start trembling or moving in slow circles, and the keyboard would randomly swap letters (you type "Hello" and it outputs "H3110"). The user would swear their hardware had gone completely mad.

2. The Fake Shutdown

Few things cause as much panic as losing your progress. This trojan perfectly simulated the Windows shutdown screen. It displayed the "Saving settings..." message and froze the screen. The user would panic thinking they hadn't saved their code, force a reboot, and upon turning it back on, everything was intact. Pure psychological torture.

1. The Desktop Pets (Nyan Cat / Desk Cat)

More of a troll adware than a destructive trojan. When executed, an animated cat (or dog) would start walking across your taskbar, meowing or chasing your cursor. The worst part? If you tried to kill the process in the Task Manager, two more cats would appear. They multiplied like Gremlins!

The Lesson Behind the Joke

Although these examples sound like mere mischief, they teach us something fundamental: the power of deception. All these trojans entered computers because the user clicked where they shouldn't have, believing they were downloading a game, a photo, or a patch.

Today, attackers no longer open your CD tray; they steal your JWT tokens or encrypt your databases.

If you want to understand how these pranks evolved into state-sponsored weapons (like the CIA case in 1982), you have to watch our latest Zero to Hero Cybersecurity episode:

👉 Watch Video: Why are Trojans the Most Dangerous Threat to a Developer?

Did you ever fall for one of these pranks back in the MSN Messenger days? Let us know in the comments!

Don't open weird files and keep learning at CodeWithBotina.