What Is Adware? How It Works and What It Can Do
Is that sudden flood of pop-ups on a work laptop just an annoyance, or a security problem? What is adware, and should a business care? Adware is software that pushes unwanted ads onto a device, and the malicious kind also tracks users, hijacks browsers and can open the door to more serious malware.
What Is Adware?
Adware is software that displays unwanted advertisements on a computer or phone, often through pop-ups, banners or browser redirects. Some adware is legitimate and ad-supported, but malicious adware installs without clear consent, tracks your browsing, slows devices and can open the door to other malware.
Adware Definition
The name comes from “advertising-supported software.” It makes money for its authors by showing ads, earning from clicks, or selling data about what users do online.
Is Adware a Virus or Malware?
Adware is not a virus, because it does not copy itself to other files or devices. Security tools usually classify it as a potentially unwanted program (PUP). Malicious adware that hides, resists removal or steals data is treated as malware.
Myth 1: “Adware Only Shows Ads”
Malicious adware does far more than display banners.
Track Browsing and Collect Personal Data
Many adware programs record websites visited, search terms, location and device details to target ads or sell to data brokers. On a business device, that browsing history can reveal clients, suppliers and internal tools.
Hijack Browsers and Redirect Searches
Browser hijackers change your home page and default search engine, inject ads into websites and redirect searches through pages that earn the author money, sometimes toward scam or phishing sites.
Deliver Malware and Open Security Holes
Adware can download other programs, display fake “your computer is infected” warnings that push scareware, or weaken security settings. Some adware installs its own certificates to inject ads into secure pages, which breaks the protection HTTPS provides.
Slow Devices and Drain Resources
Constant ads, background processes and network traffic slow computers, drain phone batteries and use up mobile data.
Myth 2: “You Only Get Adware From Shady Websites”
Adware usually arrives through ordinary routes:
- Software bundling: free tools install extra programs unless you untick a box during setup
- Fake downloads: “download” buttons on file-sharing and streaming sites that install adware instead
- Browser extensions: add-ons that seem useful, or legitimate ones later sold to new owners who add ads
- Push notifications: websites that trick users into clicking “Allow,” then send ad and scam notifications
- Mobile apps: apps, sometimes in official stores, that hide icons and show full-screen ads
Once installed, adware may add startup entries, browser extensions and scheduled tasks so it returns after a restart.
Types of Adware
Legitimate Ad-Supported Software
Free apps and games that show ads openly, with consent, and uninstall cleanly. These are a business model, not a threat, though they may still be unsuitable for work devices.
Browser Hijackers and Malicious Extensions
The most common business problem. They live inside Chrome, Edge, Safari or Firefox and change settings, inject ads and track activity.
Mac Adware
Macs are not immune. Adware for macOS often arrives through fake software updates or bundled installers and installs browser extensions and configuration profiles.
Mobile Adware on Android and iOS
Android adware families, such as the HiddenAds group, hide their icons after installation and show ads over other apps. iOS is more restricted, but users can still be hit by malicious calendar invites, configuration profiles and push-notification spam.
Adware vs Spyware vs Malvertising
| Adware | Spyware | Malvertising | |
|---|---|---|---|
| Main goal | Make money from ads | Secretly steal information | Spread malware through ads |
| Where it lives | On the device or browser | On the device | In ads on legitimate websites |
| Visibility | Usually obvious | Hidden | Looks like a normal ad |
Adware and spyware overlap when adware collects personal data, but spyware is built to stay hidden and steal.
Famous Adware Examples
- Gator (GAIN): early 2000s software bundled with free tools that tracked browsing and displayed pop-ups
- Zango: in 2006 the US Federal Trade Commission (FTC) settled charges that Zango installed adware without adequate consent, with the company agreeing to pay $3 million
- Superfish: preinstalled on some Lenovo laptops, it injected ads into encrypted web pages; the FTC reached a settlement with Lenovo in 2017
- Fireball: a 2017 browser hijacker spread through bundled software that could also run code on infected machines
- HiddenAds: a long-running family of Android adware apps
Signs of an Adware Infection
- Pop-ups appear even when no browser is open
- Home page or search engine changed without your permission
- Unknown browser extensions or toolbars
- Ads on sites that normally do not show them
- Redirects to unfamiliar sites
- New programs you did not install
- Sudden slowness, overheating or battery drain
- Constant browser notifications from unknown sites
How to Remove Adware
Remove Adware on Windows and Mac
Uninstall unfamiliar programs from Settings on Windows or Applications on Mac. On a Mac, also check Login Items and remove unknown configuration profiles. Then run a full scan with reputable anti-malware, such as Microsoft Defender on Windows, and restart.
Remove Adware From Browsers
Remove unknown extensions, reset the home page and search engine, revoke notification permissions for unfamiliar sites, and if problems remain, use the browser’s reset option.
Remove Adware From Android and iPhone
On Android, check recently installed apps, remove any you do not recognize, and revoke device admin rights if an app blocks removal. Run Google Play Protect. On iPhone, delete suspicious apps, remove unknown calendar subscriptions and profiles, and clear Safari website data.
Is Adware Legal? US and UK Rules
Ad-supported software is legal when users give informed consent and can remove it easily. In the US, the FTC has taken action against adware distributors for deceptive installation, as the Zango case shows. In the UK, the Privacy and Electronic Communications Regulations (PECR) require consent before storing or accessing information on a device, with limited exceptions, and UK GDPR applies to personal data collected. The ICO enforces both.
What Is Adware Prevention for Business? Your Checklist
So, what is adware’s real risk to a business? It is the gap it reveals: if adware can get in, so can worse. Use this checklist:
- Remove local admin rights so staff cannot install software freely
- Allowlist approved browser extensions through device management
- Block browser notification prompts by policy
- Keep endpoint protection on with PUP detection enabled
- Install software only from official sources or a company portal
- Patch operating systems and browsers
- Train staff to spot fake download buttons and “Allow notifications” tricks
For help locking down business devices, contact Cyber Security Solutions Ltd through our contact page.
FAQs
It can be. Legitimate ad-supported apps are mostly harmless. Malicious adware tracks your browsing, redirects you to scam or phishing sites, weakens security settings and can download other malware. On business devices, it also signals that unapproved software can be installed, a gap more dangerous threats can use.
Most adware is designed to show ads and collect browsing data, not to steal passwords. However, adware can redirect you to fake login pages, inject content into websites or download spyware that captures credentials. Some aggressive adware behaves much like spyware. Treat any infection seriously and change important passwords if you suspect exposure.
Yes, most modern antivirus and endpoint protection tools detect adware, often labeled as potentially unwanted programs. Some tools leave PUP detection switched off by default, so check the settings. Browser extensions and push-notification spam may not be flagged, so review extensions and notification permissions manually as well.
Only partly. Browser pop-up blockers stop many website pop-ups, but adware installed on your device or as a browser extension works around them, because it runs with its own permissions. Push notifications also bypass pop-up blockers. Removing the adware and controlling extensions and notifications is the real fix.
Adware often returns because a hidden component, startup entry, scheduled task, extension or browser sync setting was not removed. It can also come back through the same habit that caused it, such as downloading free software from unofficial sites or allowing site notifications. Scan fully, reset browsers and check synced extensions.
Yes, especially on Android, where adware apps sometimes slip into app stores disguised as games, utilities or wallpaper apps, then hide their icons. iPhones are harder to infect, but users still face spam calendar invites, malicious profiles and notification scams. Install apps only from official stores and check reviews and permissions.
