Threat Explainers · 5 min read
What Is a Trojan Horse in Computing?
A trojan is malware that gets you to install it by pretending to be something useful. Unlike a virus or a worm, it does not spread by itself — it relies entirely on persuasion.
Published 2026-08-09 · Last updated 2026-08-09
Common trojan types
Droppers exist only to fetch and install other malware. Remote access trojans give an attacker interactive control of the machine. Banking trojans intercept financial sessions. Fake antivirus trojans display invented infections and demand payment. Backdoors quietly maintain persistent access.
How trojans get in
Cracked software and game cheats, fake Flash or codec updates, installers promoted by search advertisements above the real site, and 'driver updater' or 'PC cleaner' downloads. In each case the user clicks Yes on a UAC prompt, which is why permissions are granted from the outset.
Prevention beats detection
Install software only from the developer's own domain. Be sceptical of the first sponsored search result. Never disable your antivirus because an installer asks you to — that request is itself the diagnosis.
Frequently asked questions
- Is a trojan a virus?
- Both are malware, but a virus self-replicates and a trojan relies on deceiving you into installing it.
- Can a trojan steal my banking details?
- Banking trojans are designed to do exactly that, by capturing credentials or manipulating the page you see during a session.