What are the differences between Spyware and Trojan Horse?

Let us understand the concepts of Spyware and Trojan Horse before learning the differences between them.


It is a software program which can be installed on some user's personal computer or organization without their knowledge to gather personal information or view their browsing activities.

We can defend Spyware by doing proper internet browsing, not clicking unwanted suspicious links, not clicking any download or accept buttons, and not agreeing to unwanted information.

We can remove Spyware by using proper antivirus scan. After disconnecting from the internet remove any unwanted or added programs in the control panel and reboot system and do proper antivirus scan in safe mode.

Spyware occurs in computer system like:

  • Games, videos and music which are pirated are downloading and distributing copyrighted digital content without permission.

  • Downloading content from unknown sources.

  • By accepting pop-up advertisements.

  • By opening email attachments from unknown senders.

The prevention methods from spyware are as follows :

  • We have to download software only from trusted sources.
  • Try to read all disclosures when installing software.
  • Try to avoid interactions with pop-up ads.
  • Don’t open the email attachments from unknown senders.
  • Use trusted antivirus software and reputable spyware tools.

Types of Spyware

The different types of spywares are as follows −

  • Adware − Any application which displays advertisements when the program is running. For example: pop-up windows, banners.

  • Keyboard loggers − It is a type of surveillance technology used to monitor and record keystrokes. Cyber criminals can use these to steal sensitive information.

  • Mobile spyware − It is a type of spyware which can infect mobile devices that enters via SMS or MMS communication channels.

Trojan or Trojan Horse

It is malicious software. These softwares are developed by hackers to gain illegal access to the victim's system.

These malicious softwares are used by cyber criminals or hackers for personal or sensitive information. Computers can be infected with a Trojan horse in different ways. For example by downloading pirated versions of software or games.

By emails or opening some links in some may also get infected your computer with Trojan Horse. The word trojan horse is derived from the Ancient Greek story of the wooden horse that was used to help Greek troops invade the city of Trop by stealth.

Purpose and Uses

If installed and run with elevated privileges, a Trojan will generally have unlimited access.

A trojan horse is a Remote Administration Tool (RAT). This is something extremely dangerous. It has full control of the victim's PC to the attacker.

It has two parts −

  • Client part
  • Server part


The major differences between Spyware and Trojan Horse are as follows −

SpywareTrojan Horse
We can install spyware for commercial useTrojan is installed for malicious purposes.
It is less harmfulIt is more harmful
The purpose of spyware is to monitor the activity of systemThe purpose of Trojan is to control the activity of the system.
It cannot be detected by antivirus software.It can be detected by antivirus software.
Examples: Cydore, Download wareExamples: Rootkit, Back orifice etc.