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)

    All A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

      • Related Articles

      • EDR (Endpoint Detection and Response)

        What it is EDR is your always-on security team for laptops and servers. It watches what’s happening on each device, spots attacks in progress, and helps you respond fast - quarantine, investigate, and clean up. For details on capabilities and use ...

      • NDR (Network Detection And Response)

        What it is Network Detection and Response (NDR) watches live network traffic to spot and investigate suspicious behavior in real time. Instead of relying on signatures, it analyzes patterns and anomalies to catch threats moving across your ...

      • XDR (Extended Detection and Response)

        What it is XDR is a security system that watches your company’s devices, email, cloud, and network together and connects the dots. Instead of separate tools, XDR pulls all the signals into one place, spots attacks faster, and can auto-block bad ...

      • Data Execution Prevention

        What it is Data Execution Prevention (DEP) is a Windows safety net that stops code from running in places it shouldn’t—like the stack or heap. If malware tries to execute from those memory areas, Windows blocks it and shuts the app down instead of ...

      • Data Breach Prevention

        Why it matters Breaches drain money, trust, and time. Strong basics turn scary “what ifs” into non-events: a phish gets ignored, a stolen password is useless, a lost laptop holds only encrypted gibberish. The short, smart checklist MFA everywhere: ...