06.07.26

How to tell if a third-party app is safe before you download it

Every app on your phone is a doorway—and not all of them lead somewhere safe. When you download a new app, it almost always requests access to personal information on your device: your camera, contacts, location, photos, and more. If you deny those permissions, the app may limit its features or stop working altogether. That puts you in a tough spot—which is exactly why you need to be selective about what you install in the first place.

Why third-party apps are a growing security risk

Not every app in the store is what it claims to be. Cybercriminals routinely disguise malware as everyday tools—flashlight apps, PDF readers, QR code scanners, and productivity utilities. Once installed, these apps can steal your data, spy on your activity, serve aggressive ads, or even drain your bank account.

The scale of this threat is massive. According to a 2025 report by Zscaler ThreatLabz, researchers identified 239 malicious apps on the Google Play Store that were collectively downloaded over 42 million times, with Android malware transactions surging 67% year-over-year. And that’s just what made it past official store protections—apps downloaded from third-party sources outside the Play Store or App Store carry even greater risk.

How to decide if an app is worth downloading

Before you tap “Install,” run through this quick checklist:

  • Have you heard of it before? Stick to apps you recognize or that come recommended by trusted sources. A well-known app with millions of downloads is far less likely to be hiding malware than an obscure one with a handful of reviews.
  • Who made it? Check the developer’s name. Reputable companies have verified developer profiles and a track record of other published apps. An unknown developer with only one app in the store is a red flag.
  • Do the reviews look real? Watch out for apps with suspiciously generic five-star reviews or very few ratings. Legitimate apps typically have detailed, mixed feedback from real users.
  • Are the permissions reasonable? A photo editing app needs your camera and photos—that makes sense. A calculator app asking for your contacts, microphone, and location? That doesn’t.
  • Is there a simpler alternative? If your phone already has a built-in tool that does the same thing—like a flashlight, calculator, or notes app—skip the third-party download entirely.

What to do after you install a new app

Even after you’ve done your research, stay vigilant:

  • Review permissions immediately. Go into your phone’s settings and check exactly what access you’ve granted. Revoke anything that doesn’t match the app’s core function.
  • Monitor your device’s behavior. If your phone suddenly slows down, heats up, or starts showing unexpected ads after installing an app, uninstall it right away.
  • Keep apps updated. Legitimate developers push regular updates to patch security vulnerabilities. An app that hasn’t been updated in months may no longer be safe.
  • Delete what you don’t use. Every unused app is a potential attack surface sitting idle on your device. If you haven’t opened it in a month, remove it.

Your phone holds your most personal information—from banking details and private messages to photos and location history. Every app you install gets a piece of that access, so treat each download like a decision that matters. Stick to well-known, reputable apps, scrutinize permissions before you grant them, and when in doubt, skip the download entirely. A little caution upfront is always easier than dealing with malware after the fact.