WHATSAPP users are being warned over a dangerous type of “malware” that swaps your chat app with a hacked version.
Experts warn that 25million WhatsApp users who own Android smartphones have been affected – putting them at risk of being spied on by hackers.
The malware is called “Agent Smith”, and replaces your WhatsApp with a dodgy version that serves you up advertisements – earning money for crooks.

However, experts say the malware leaves you open to more dangerous hack attacks, and could hand your private info to hackers on a plate.
For most users, the fake WhatsApp will simply be a major nuisance.

It will serve up “malicious” ads at random times, which are difficult or impossible to quit.

Fake WhatsApp? How to check if yours is dodgy...
Here's what you need to know... The main way to spot a problem is if you notice ads at weird times.In particular, if you receive ads when you open WhatsApp then there’s a problem.That’s because the standard version of WhatsApp doesn’t serve ads – though some users may see ads in Stories.If you suspect a dodgy app, check your app list for suspicious items like Google Updater or Google Installer. If you find one, uninstall it.If you have an infected app, follow these steps…Android:
Go to Settings Menu
Click on Apps or Application Manager
Scroll to the suspected app and uninstall it
If it can’t be found then remove all recently installed apps
Once that’s done, uninstall WhatsApp from your phone and reinstall it completely through the official Google Play Store.Don’t forget to back up your chats before your uninstall WhatsApp, or you risk losing them.