What is a Trojan Horse? - Definition:
A Trojan horse, often known as a Trojan, is a form of malware that masquerades as genuine software. Cyber-thieves and hackers can use Trojans to obtain access to a user’s computer system. Social engineering is commonly used to persuade users to download and run Trojans on their computers. Trojans can be used by cybercriminals to spy on you, steal your personal data, and get backdoor access to your system once they’ve been launched.
How do Trojans work?
To complete its job, a Trojan must be executed by the victim. Trojan malware can infect machines in a number of ways, including:
- By opening an infected email attachment or clicking on a link to a malicious website, a user becomes a victim of phishing or other social engineering attacks.
- A pop-up advertising a phoney antivirus program appears, claiming that your computer is contaminated and inviting you to run a program to clear it up. This is referred to as “scareware.” Users are, in fact, downloading a Trojan onto their devices.
- A user visits a malicious website and experiences a drive-by download pretending to be helpful software.
- A user downloads a program whose publisher is unknown from an untrustworthy website.
- Attackers install a Trojan through exploiting a software vulnerability or through unauthorized access.
- Hackers build a bogus Wi-Fi hotspot network that appears to be the one to which a user is attempting to connect. When a person connects to this network, they may be led to bogus websites that have browser exploits that will reroute any file they attempt to download.
Types of Trojan Viruses?
How Trojans impact you...
Trojans are masters at concealment. They entice people to instal them, then work behind the scenes to accomplish their goal. You may not even realise you’ve been a victim until it’s too late. If you think your device has been infected with Trojan virus, keep an eye out for the following signs:
- Poor device performance – for example, running slowly or frequently crashing (including the infamous “blue screen of death”)
- The desktop has changed – for example, the screen resolution has altered, or the color appears different
- The taskbar has changed – or disappeared altogether
- Unrecognised programs appear in your task manager
- An increase in pop-ups –
- Being redirected to unfamiliar website when browsing online
- An uptick in spam emails
Some Trojans can be removed by deactivating start-up items on your computer that don’t come from a trusted source. To do so, reboot your device into safe mode, which will prevent the Trojan from preventing you from deleting it.
Make sure you know the apps you’re uninstalling because removing essential programmes from your computer could cause it to slow down or shut down.
How to protect yourself against Trojans
As always, the greatest protection against Trojan malware is a mix of complete antivirus protection and excellent cybersecurity hygiene:
- Be cautious about downloads. Never download or install software from a source you don’t trust completely.
- Be aware of phishing threats. Never open an attachment, click a link, or run a program sent to you in an email from someone you don’t know.
- Update your operating system’s software as soon as the updates are available. In addition to operating system updates, you should also check for updates on other software you use on your computer. Updates often include security patches to keep you safe from emerging threats.
- Don’t visit unsafe websites. Look out for sites that have security certificates – their URL should start with https:// rather than http:// – the “s” stands for “secure” and there should be a padlock icon in the address bar too.
- Avoid clicking pop-ups and banners. Don’t click on unfamiliar, untrusted pop-ups warning you your device is infected or offering a magical program to fix it. This is a common Trojan horse tactic.
- Protect accounts with complex, unique passwords. A strong password is not easy to guess and ideally made up of a combination of upper- and lower-case letters, special characters, and numbers. Avoid using the same password across the board and change your password regularly. A password manager tool is an excellent way to manage your passwords.
- Keep your personal information safe with firewalls. Firewalls screen data that enters your device from the internet. While most operating systems come with a built-in firewall, it’s also a good idea to use a hardware firewall for complete protection.
- Back up regularly. While backing up your files won’t protect you from downloading a Trojan, it will help you should a malware attack cause you to lose anything important.
By installing effective antivirus software, you can defend your devices – including PCs, laptops, Macs, tablets, and smartphones – against Trojans.