That old PDF reader, browser extension, meeting app, or remote-access tool you installed years ago may seem harmless. But if it still runs on your device and no longer receives security updates, hackers can use known vulnerabilities to steal data, install malware, or gain control of your computer.
Why is outdated software a security risk?
Software vulnerabilities are weaknesses in an application’s code or configuration. Once developers discover a vulnerability, they usually release a security update, or patch, to fix it. Hackers study those patches and public vulnerability reports to identify computers still running the unsafe version.
The risk grows when you forget an application is installed. Because you no longer open it, you may not notice update notifications, security warnings, or announcements that the developer has discontinued support.
According to CISA’s software update guidance, exploitation of vulnerabilities provided initial access in 20% of the breaches analyzed in Verizon’s 2025 Data Breach Investigations Report, a 34% increase from the previous year.
How can hackers exploit forgotten applications?
Attackers may target old software through several methods:
- Known security vulnerabilities: Hackers use publicly available information or automated tools to find devices running vulnerable versions.
- Malicious files: An outdated document reader or media player may execute harmful code when you open a specially crafted file.
- Unsafe browser extensions: Abandoned extensions may contain vulnerabilities, collect browsing data, or change ownership without your knowledge.
- Exposed remote-access software: Old remote desktop tools can provide a direct path into your computer.
- Unsupported operating systems: Once support ends, newly discovered vulnerabilities may never receive patches.
CISA maintains a Known Exploited Vulnerabilities Catalog that tracks flaws confirmed as exploited in real-world attacks and recommends prioritizing their remediation.
How do you find software you forgot was installed?
Conduct a quick application audit every three months.
On Windows:
- Open Settings.
- Select Apps, then Installed apps.
- Sort the list by installation date, size, or name.
- Research unfamiliar applications before removing them.
On macOS:
- Open Finder.
- Select Applications.
- Review every installed program.
- Use the developer’s uninstaller when one is available.
Also inspect your browser’s extension page, startup applications, system tray, and remote-access tools. Do not remove system components simply because you do not recognize their names. Search the exact application and publisher first.
What should you update or uninstall?
Use this simple rule: Update what you need and remove what you don’t.
Take action when software:
- Has not been used in several months
- No longer receives security updates
- Comes from an unknown or untrusted developer
- Duplicates a feature already built into your device
- Requests unnecessary permissions
- Starts automatically without a valid reason
Turn on automatic updates for your operating system, browsers, security software, productivity tools, and frequently used apps. CISA calls regular updates and patches two of the simplest and most effective ways to protect devices and data.
Hackers love forgotten software because it can quietly preserve vulnerabilities long after you stop using the program. Review your installed applications regularly, remove unused tools, replace unsupported products, and install security updates promptly. A cleaner device is not only faster and easier to manage. It also gives attackers fewer places to hide and fewer ways to get in.
