Antivirus – How Does It Work?
Antivirus is software that protects your computer, smartphones, tablets and any other devices you use to connect to the internet from viruses and malware. Antivirus software combines prevention, detection and removal of malicious programs.
Most antivirus software uses what’s called signature-based detection. Each file has the digital equivalent of a thumbprint. When security professionals find a new virus type, they share its thumbprint with antivirus software so the program knows to flag it for inspection. The software scans your device looking for files with the suspicious thumbprint, then quarantines or deletes the file before it can infect your system. Antivirus software also regularly updates its virus definitions to make sure it’s catching all the latest malware.
But even the best antivirus software can sometimes misidentify a secure piece of code or program as a threat. This is called a false positive and it can cause your antivirus program to erroneously quarantine or delete a useful program or file.
Modern, up-to-date antivirus programs use a combination of signatures, heuristic analysis and other technologies to spot new malware. They can also perform cloud analysis, which sends suspected viruses to a vendor’s servers so they can be tested and verified as safe or dangerous.
Some for-purchase antivirus products add features that address more contemporary concerns, such as monitoring whether your passwords have been leaked on the dark web or alerting you if criminals are trying to steal your personal information. But free antivirus programs generally cover the basics.