How Does Anti-Spyware Work?

By Contributing Writer

Updated July 21, 2017

Anti-Spyware Software

Spyware is the name given to a variety of harmful programs that secretly install themselves on a computer without the user's consent. Once installed, this spyware software gathers information about the user, everything from personal data to his Internet browsing habits.

Anti-spyware software alerts users to the existence of spyware and then gives them the choice of quarantining or removing the offending file or files, directories and registry keys affected by the spyware. Naturally, then, anti-spyware software is a highly recommended security step for any computer owner. Similar to the software that is used to detect and remove viruses, these protection programs work in a variety of ways.

Hard Disk Scan

One effective technique of anti-spyware software is to run a hard disk scan. Using a database of known spyware, in a hard disk scan your protection program searches all the files in your computer’s hard drive for matches. Like any program, spyware leaves what is known as a signature or fingerprint in the operating system’s registry. (Some anti-spyware programs only look through the file or directory names on the hard drive and so sometimes miss spyware that has disguised itself under a different name.)

Logically, the larger the database of known spyware that a particular anti-spyware software employs, the better it is at detecting. For this reason, anti-spyware software is updated frequently, with ever expanding databases to keep up with the new harmful spyware being put out onto the Internet all the time. Because of this, anti-spyware software is often sold on a subscription basis.

Registry and Memory Scans

In a registry scan, another technique, the anti-spyware software searches for modifications made by the spyware to Windows configuration files. A memory scan involves the software checking processes that are running on the computer for signs of spyware activity.

Monitoring URLs

Another common technique of anti-spyware software is to monitor URLs. By keeping track of websites visited and monitoring cookies against a database of known spyware, this type of security can also, like the techniques above, locate spyware and alert the user to its existence.