Types of Computer Anti-Virus Software

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Anti-virus software refers to computer programs designed to detect and eliminate malicious software, known as malware. While people use different definitions of different types of malware, including what constitutes a virus, a worm or another unwelcome intrusion, most anti-virus software is designed to eliminate wide swaths of malware. Different types of anti-virus software exist with differences in the computers they work on, how they search for viruses and what they do when they find them.


Common Types of Anti-Virus Software

The most common types of anti-virus software are designed to run on a single computer or smart phone. They search for malware to prevent it from doing damage and remove it. Microsoft Windows includes Microsoft's Windows Defender anti-virus software, and other software is available from companies such as Symantec, McAfee and Malwarebytes.

Many anti-virus vendors make versions of their products for various common operating systems, including Microsoft Windows, Apple macOS, Linux and the smart phone operating systems Android and iOS. Some free anti-virus software is available, some is available for a single purchase, and some is available on a subscription basis with updates to handle new types of viruses and malware as they appear.


Differing Approaches to Anti-Virus Software

Traditionally, anti-virus software uses what are called malware signatures, which are digital fingerprints of malicious software, to detect and disable unwanted programs before they can do damage. This approach works well at eliminating known viruses, but it has limitations when handling new attacks from previously unknown malware because anti-virus developers haven't incorporated the virus signatures into their products.

Other types of anti-virus software attempt to monitor software and computers for unusual behavior, such as sudden bursts of data usage, attempts to access wide swaths of files on a hard drive or connections to unfamiliar sites. Some newer types also use machine learning techniques to determine what looks like normal behavior on a computer or network and limit activities by programs or computers that are acting strangely. Some of this security software is designed to run across an entire commercial network rather than running independently on separate devices.


Anti-virus software is commonly included in email services, where it scans message attachments for suspicious files. Email is a common way for viruses to spread from computer to computer. Anti-virus software is also available for corporate firewall computers, where it can detect suspicious code attempting to either enter or exit the network, ideally before it does harm.