Experts at security firm Sophos are warning Android phone owners about 22 dodgy apps that drain battery life and could result in a big phone bill.
The Sun reported the "click-fraud" apps pretend to be normal apps on the Google Play Store, but secretly perform criminal actions out of sight.
The 22 apps have been collectively downloaded more than 22 million times.
"From the user's perspective, these apps drain their phone's battery and may cause data overawes as the apps are constantly running and communicating with servers in the background," researchers told The Sun.
Warning signs include increased data usage and fast-draining battery life, however, pinning such issues to a particular app is hard.
While Google removed the dodgy apps from the Play Store on the week of November 25, they can still operate if already installed on an Android phone.
There are the apps you should uninstall right now:
• Sparkle FlashLight — com.sparkle.flashlight
• Snake Attack — com.mobilebt.snakefight
• Math Solver — com.mobilebt.mathsolver
• ShapeSorter — com.mobilebt.shapesorter
• Tak A Trip — com.takatrip.android
• Magnifeye — com.magnifeye.android
• Join Up — com.pesrepi.joinup
• Zombie Killer — com.pesrepi.zombiekiller
• Space Rocket — com.pesrepi.spacerocket
• Neon Pong — com.pesrepi.neonpong
• Just Flashlight — app.mobile.justflashlight
• Table Soccer — com.mobile.tablesoccer
• Cliff Diver — com.mobile.cliffdiver
• Box Stack — com.mobile.boxstack
• Jelly Slice — net.kanmobi.jellyslice
• AK Blackjack — com.maragona.akblackjack
• Colour Tiles — com.maragona.colortiles
• Animal Match — com.beacon.animalmatch
• Roulette Mania — com.beacon.roulettemania
• HexaFall — com.atry.hexafall
• HexaBlocks — com.atry.hexablocks
• PairZap — com.atry.pairzap