Whatsapp your friend with a message containing nearly 4000 smileys and the friend will suffer with a crash everytime s/he opens the message. The recent bug tested on Android devices by multiple brands and caused the WhatsApp to crash. WhatsApp for Android devices including Marshmallow, Lollipop and Kitkat and WhatsApp Web for Chrome, Opera and Firefox web browsers are affected by this bug. There is a PoC video demonstration too and you can watch that here: https://youtu.be/hEMD5y3WGt4 The best way to protect yourself is deletion of conversation when such message is received. If you become a victim of such message on WhatsApp, just open your messenger and delete the whole conversation with the sender. However, remember, if you have kept some records of your chat with that particular friend, you’ll end up losing them all. This trick will be famous and users will be vulnerable until a patch is released by the Facebook Inc.