What Is a Trojan Horse?

A Trojan horse is a type of virus that appears to have a benign purpose but performs malicious functions under that guise. At this point we can say that Trojans actually use techniques designed to deceive users. Trojans (also called trojans) are the most frequently encountered malware. Deceptions are used to make you install malicious applications on your system. They can be considered one of the most dangerous types of virus.

You can find many useful tools for users on the internet. Many applications such as screensavers, images and documents are also offered free of charge. Of course, cyber attackers can exploit this situation to their advantage and present a malicious application to you as a good and useful tool. Trojans use various methods to conceal their true purpose.

The First Known Trojans

One of the first known Trojans is ransomware, which remains the bane of organisations to this day. The first ransomware, known as the AIDS Trojan, was distributed with the claim that it contained a database about the AIDS disease. Once loaded, this trojan would count 90 boot cycles on infected computers. When this cycle was completed, it became active and encrypted most of the filenames in the root directory of the machine. Victims were of course asked to send $189 or $378 to a PO box in Panama to recover their data. Trojans are named after the famous wooden horse from Greek mythology used to infiltrate the city of Troy.

What Can Trojans Do?

Among the following list of items, opening a backdoor and executing DDoS attacks are probably the most common outcomes of a Trojan attack. However, the capabilities of Trojans extend further. Most common actions carried out by Trojans include:

• Opening a backdoor on the infected system for remote access
• Using the infected machine to launch DDoS attacks
• Downloading and installing additional malware
• Stealing sensitive information such as passwords, banking credentials and personal data
• Encrypting files for ransom (ransomware)
• Using the machine as part of a botnet
• Spying on users via the camera or microphone
• Deleting, modifying or encrypting data

How Can You Tell If Your System Is Infected?

It is difficult to determine whether your system has been infected by a Trojan. However, there are some symptoms that suggest a Trojan is present on the system. Of course, it is necessary to assume that you or another legitimate user did not make these changes:

• Changes to the desktop wallpaper or browser homepage without your knowledge
• Unknown programs appearing in the task manager or startup items
• New toolbars or browser extensions installed without your knowledge
• Unusual network activity or slow internet connection
• Antivirus software being disabled or unable to run
• Pop-up windows appearing frequently
• Unusual activity on accounts (unauthorised logins, password changes)

Protecting Against Trojans

Protecting yourself against Trojan horses requires a combination of technical measures and good security practices. Keep your operating system and software up to date with the latest security patches. Use reputable antivirus software and keep it updated. Be cautious about downloading software from untrusted sources. Never open email attachments from unknown senders. Be alert to social engineering tactics that try to persuade you to click malicious links or download files. Regularly back up important data so that you can recover if a ransomware attack occurs.