What is spyware, adware, and malware, and how does it get on my system?

Spyware is software that gathers information about you, your browsing and internet usage habits, as well as other data. Adware is software that displays advertising banners, redirects you to websites, and otherwise conducts advertising on your computer (not to be confused with popup ads, which come from the websites that you visit). Malware is malicious software that is intended to do harm to your computer or software. Malware includes viruses, Trojans, and worms.

Many users inadvertently download spyware or adware when downloading other programs. Many popular peer to peer applications and other software packages include adware or spyware packages. Even seemingly innocuous programs such as special cursors can contain spyware. In addition, many websites and advertising banners set cookies on your system that track your web usage.

Why is it a danger?

Spyware and adware can gather information about you, your browsing habits, as well as other data. Cookies set by websites can allow these applications to track which websites you visit; this is especially dangerous because some cookies can contain user login and password information for the website which created it. In addition, spyware and adware can slow your system down, hog system resources, and use network bandwidth. Some spyware and adware can even be malware and open your system to attack or cause system problems.

What can you do about it?

  • Download and run an adware- or spyware-removal program. Links to a number of popular removal and protection programs are included below.
  • Set Internet Explorer (IE) browser settings to appropriate security levels and disable or prompt for access for ActiveX and other dangerous content. Consider using alternate browsers such as Mozilla, Netscape, Opera, or Safari (MacOS).
  • Use antivirus software and update it regularly. Purdue provides free antivirus software for use by students, staff, and faculty. It can be downloaded at the SecurePurdue Downloads page.
  • Do not download suspicious programs, and check programs before you install them. Websites that pop up messages asking you to download software should not be trusted unless you know what that software is or unless you requested it. Often, choosing the “advanced” or “custom” install for software will allow you to de-select components and you can remove adware and spyware from the installation process.
  • Use a software firewall to help control which applications can send or receive data. This can help you prevent a spyware or adware program from contacting its owner and transmitting your personal informationand can also tell you if you are sending that information.


  • Spyware
    Spyware is any technology that aids in gathering information about a person or organization without their knowledge.
  • Malware
    Malware or malicious software is programming or files that are developed for the purpose of doing harm. Thus, malware includes computer viruses, worms, and Trojan horses.
  • Adware
    Adware is any software application in which advertising banners are displayed while the program is running
  • Trojans
    Trojan horses are malicious programs typically contained in otherwise innocent seeming programs or data. These programs attempt to take control of a system or attempt to do damage to the system or its data.
  • Software
    Spyware and Adware removal tools
  • Ad-Aware
    https://www.lavasoft.com/Ad-aware searches your system for adware, cookies, and some spyware programs, and allows users to remove any files or programs found.
  • SpyBot-S&D
    https://www.safer-networking.org/SpyBot-S&D is a spyware and adware detection and removal tool.
  • OptOut
    OptOut is a spyware detection and removal program.


  • Zone Alarm
    Zone Alarm is a commercial software firewall that also provides a free version for personal use.
  • ICF
    Windows XP includes ICF, the Internet Connection Firewall.

Spyware and Adware Removal Help Website: