Trojan Virus - what it is, classic tricks, and how to avoid and remove it

Trojan Virus

What it is

A trojan is malware that pretends to be something helpful (an app, document, or script) but does something harmful once you run it. Unlike a worm or classic “virus,” a trojan doesn’t spread by itself - it needs you to open or install it. Common trojan families steal passwords, spy on activity, or pull in more malware. Overview and examples: https://gridinsoft.com/trojan

Why it matters

One click can give criminals a foothold on your PC - leading to stolen logins, drained accounts, or even a later ransomware hit.

How it works 

  • Disguise: arrives as a “must-have” app, crack, driver, invoice, or update.

  • Execute: you open it; the trojan runs and installs quietly.

  • Payload: steals data, spies, changes settings, or downloads more malware.

  • Persist: adds startup entries or tasks so it returns after reboot.

Red flags

  • Prompts to disable antivirus or run as admin for a “viewer/codec.”

  • Files from torrents or random sites that ask for unusual permissions.

  • New tray icons, toolbars, or background network traffic you don’t recognize.

  • Passwords suddenly stop working or you see logins from new locations.

Do it right

  • Get software and updates only from official vendor sites or trusted stores.

  • Don’t open unexpected attachments; scan downloads before running.

  • Keep Windows, your browser, and security tools updated with real-time protection on.

  • If you suspect a trojan: disconnect from the internet, run a full scan, change passwords from a clean device, and remove unknown startups; reimage if problems persist.

    Glossary (A–Z)

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