Why does it matter?
Four Android apps, HotSpotVPN, Free VPN Master, Secure VPN, and CM Security Applock AntiVirus, were discovered to commit ad fraud by pushing ads when apps were running in the background, or outside the app environment.
Adware activity details
The four Android applications were analyzed by Andy Michael, who first reported the behavior.
“This application takes it a step further. Instead of constantly showing the ads the app leverages its enormous user base and intrudes less often and randomly. It uses a more sophisticated approach by popping up the app instead and showing the ads immediately after you try to get back to the home screen,” says Michael about the Security Master application.