Threat Explainers · 5 min read
What Is Adware and Why Does Antivirus Ignore It?
Adware is software that generates revenue from your attention or your browsing data, usually installed alongside something you actually wanted.
Published 2026-08-09 · Last updated 2026-08-09
How adware gets installed
The dominant route is bundling: a free utility's installer offers additional software, pre-ticked, on a screen designed to be clicked past. Choosing custom installation instead of express reveals and disables it.
What it does once installed
It injects advertisements into pages, redirects searches through affiliate networks, opens pop-ups outside the browser and profiles browsing behaviour to sell as audience data.
Why antivirus often leaves it alone
Adware is usually distributed by a real company with a EULA that the user technically accepted. Flagging it creates legal and false-positive risk, so classic engines classify it as potentially unwanted at most, and antimalware scanners do the aggressive work.
Adware vs browser hijacker vs spyware
Adware monetises advertising; a hijacker specifically enforces search and homepage settings; spyware covertly collects sensitive data. One bundle often delivers all three, which is why cleanup should always cover every category.
Frequently asked questions
- Is adware a virus?
- No. It does not self-replicate. It is unwanted software, and it is removable with an on-demand antimalware scanner plus browser cleanup.
- Can adware steal passwords?
- Adware itself usually harvests browsing data rather than credentials, but it commonly ships alongside components that do more.