Used Device Security Check

TL;DR

Buying used devices can save money, but they might have security risks left behind by previous owners. This guide shows you how to check for and remove those risks before using the device.

Checking a Used Device for Security Risks

1. Initial Visual Inspection: Look for physical damage or tampering. Has it been opened? Are there any unusual stickers covering ports or screws?
2. Power On and Factory Reset: This is the first crucial step.
   • Turn on the device.
   • Navigate to Settings (usually under General, System, or similar).
   • Find the option for “Reset” or “Factory Data Reset”. The exact wording varies by device and operating system.
   • Important: Back up any data you want to keep *before* resetting if possible, but be aware that previous owner’s data may still exist.
3. Check the Operating System Version: An outdated OS is a security risk.
   • Android: Settings > About Phone > Software Information (or similar). Check for available updates.
   • iOS/iPadOS: Settings > General > Software Update. Install any pending updates.
   • Windows: Start Menu > Settings > Update & Security > Windows Update. Check for and install updates.
4. Scan for Malware (if possible): Not all used devices will allow malware scans.
   • Android: Install a reputable antivirus app from the Google Play Store (e.g., Bitdefender Mobile Security, Norton 360). Run a full scan.
   • iOS/iPadOS: iOS is generally more secure and less prone to malware, but you can still use security apps for features like Wi-Fi scanning and phishing protection.
   • Windows: Windows Defender (built-in) or install a third-party antivirus program (e.g., Malwarebytes). Run a full scan.
5. Review Installed Applications: Look for anything unfamiliar or suspicious.
   • Android: Settings > Apps & Notifications > See all apps. Uninstall any apps you don’t recognize or trust.
   • iOS/iPadOS: Settings > General > iPhone Storage (or iPad Storage). Uninstall unwanted apps.
   • Windows: Start Menu > Settings > Apps & Features. Uninstall suspicious programs.
6. Check Account Connections: Ensure no accounts are linked to the previous owner.
   • Android: Settings > Accounts. Remove any Google accounts or other services you don’t recognize.
   • iOS/iPadOS: Settings > [Your Name] > iCloud, Mail, Contacts, Calendars etc. Check for and remove unwanted accounts.
   • Windows: Start Menu > Settings > Accounts > Email & Accounts. Remove any linked email or social media accounts.
7. Check Browser History and Saved Passwords: Clear these for privacy.
   • Use the browser’s settings to clear browsing data (history, cookies, cached images and files).
   • If password management is built-in, remove any saved passwords.
8. Check Wi-Fi Networks: Remove previously connected networks.
   • Android: Settings > Network & internet > Wi-Fi > Saved networks. Forget unwanted networks.
   • iOS/iPadOS: Settings > Wi-Fi. Tap the ‘i’ next to a network and choose “Forget This Network”.
   • Windows: Start Menu > Settings > Network & Internet > Wi-Fi > Manage known networks. Forget unwanted networks.
9. Check Bluetooth Connections: Remove paired devices.
   • Android: Settings > Connected devices > Previously connected devices. Unpair any unknown devices.
   • iOS/iPadOS: Settings > Bluetooth. Tap the ‘i’ next to a device and choose “Forget This Device”.
   • Windows: Start Menu > Settings > Devices > Bluetooth & other devices. Remove unwanted paired devices.
10. Consider Professional Data Wiping (Optional): For sensitive data, a professional service can ensure complete data removal.

Disclaimer: These steps reduce risk but don’t guarantee complete security. Always be cautious when using used devices and avoid storing highly sensitive information on them.