Instant messaging apps like WhatsApp and Telegram have quickly caught on to become the de-facto standard for communication online these days, and with the implementation of features such as end-to-end encryption, the conviction that these messaging apps are completely safe, even for confidential and personal messaging, has only strengthened over time.
The blog post goes on to give some examples of how app developers can try and prevent a hack such as this from affecting their apps. Symantec suggests that app developers employ techniques such as verifying file integrity with hashes and checksums, storing media files in internal memory to prevent other apps and malicious actors from accessing them, and encrypting media files.
The blog also gives some tips for end-users to try and mitigate these hacks from affecting them. For WhatsApp users, the company recommends heading over to Settings -> Chats -> Media Visibility and turning the toggle off.
