Downloader Trojan: What it is, how it slips in, and how to remove it safely

Downloader Trojan

What it is

A downloader trojan is a malware dropper: it sneaks in looking harmless, then quietly downloads and runs more malware - ransomware, stealers, spyware, you name it. Think of it as the first domino in an infection chain. Learn more in our 
downloader trojan explainer

What you may notice

  • New processes or apps you didn’t install

  • Sudden pop-ups, redirects, or extensions appearing

  • CPU/disk spikes and security tools turning off or failing to update

How it gets in

  • Fake updates and bundled “free” installers

  • Phishing attachments or links (archives, scripts, macros)

  • Malvertising and drive-by downloads from sketchy sites

Remove it now (quick steps)

  1. Disconnect from the internet to stop more payloads.

  2. Run a full anti-malware scan; quarantine everything found and reboot.

  3. Check startup items, scheduled tasks, services, and browser extensions; remove unknowns.

  4. From a clean device, change passwords and enable MFA (in case a stealer was dropped).

  5. Review firewall/DNS logs for domains contacted and block them.

Prevent it

  • Install software only from official sources; avoid cracks and “free” codecs.

  • Keep OS, browsers, and plugins patched; block macros by default.

  • Use reputable EDR/anti-malware and email/web filtering.


    Glossary (A–Z)

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