---
title: "PUP"
description: "A PUP (Potentially Unwanted Program) installs alongside other software and toes the line of malware. Learn the common types, risks and how to remove them."
url: "https://nodea.io/en/glossary/pup-potentially-unwanted-program"
lang: "en"
updated: "2026-07-13"
---

# PUP

> A PUP (Potentially Unwanted Program) is software that usually arrives bundled with another install and behaves on the borderline between a normal app and malware.

A **PUP** (Potentially Unwanted Program) is software that typically lands on a device bundled with another, legitimately installed application and performs actions the user never knowingly agreed to. A PUP sits on the boundary between an ordinary app and malicious code — it is not always clearly harmful, but it tends to be intrusive, slows the system down and undermines privacy.

## How a PUP works

The most common categories of potentially unwanted programs are:

- **Adware** — floods the screen with ads and injects banners into the browser (see [adware](https://nodea.io/en/glossary/adware)).
- **Toolbars** — attach to the browser and swap the default search engine and home page.
- **Browser hijackers** — redirect searches to pages of their own.
- **Optimizers and "cleaner" tools** — scare users with fake errors to push a purchase.
- **Data-collecting software** — tracks activity and profiles the user without clear consent.

The main infection vector is *bundling* — attaching a PUP to the installer of free software. During a quick "next, next" install, the user unknowingly accepts extra "offers" hidden in the wizard.

## PUPs in practice

From a security standpoint, PUPs are treated as a real risk:

1. **Detection** — antivirus engines keep a separate "PUP/PUA" detection category you can enable in settings.
2. **Removal** — uninstall from the operating system, clean out browser extensions, and run a dedicated anti-malware scan.
3. **Prevention** — download from official sources, use custom installs and deselect add-ons, and keep the OS and browser updated.

Although a PUP is rarely as dangerous as [ransomware](https://nodea.io/en/glossary/ransomware) or an [exploit](https://nodea.io/en/glossary/exploit), it can be a gateway to further infections — so it is worth removing as soon as it is detected.

### Is a PUP a virus?

Technically no. A PUP does not self-replicate like a virus or encrypt data like ransomware, which is why antivirus tools classify it separately. It can still be intrusive and privacy-invasive, so most scanners flag it and offer removal.

### How do I avoid installing a PUP?

Download software only from official sources and choose the custom install option, unchecking extra "offers". An up-to-date antivirus with PUP detection plus caution around installers from free-software portals sharply reduce the risk.

## Related

- [Adware](https://nodea.io/en/glossary/adware)
- [Ransomware](https://nodea.io/en/glossary/ransomware)
- [Phishing](https://nodea.io/en/glossary/phishing)
- [Keylogger](https://nodea.io/en/glossary/keylogger)
- [Exploit](https://nodea.io/en/glossary/exploit)

---

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