While they’re known for strongly encrypting messages in transit, apps like WhatsApp and Telegram may not always be able to keep files safe after they’re on your phone. Today, researchers from Symantec explain how hackers could use a malicious app to subtly alter media files sent through the services.
On Android, apps can choose to save media, like images and audio files, through either internal storage that’s only accessible through the app, or external storage which is more widely available to other apps. WhatsApp, by default, stores media through external storage, and Telegram does so when the app’s “Save to Gallery” feature is enabled.
