New Delhi, Apr 23 (IANS): Global cybersecurity firm Avast on Tuesday announced that it has discovered 40 adware apps on the Google Play Store with over 20 million downloads.

The identified adware persistently displays full screen ads, and in some cases, tries to convince the user to install further apps.

"Avast has contacted Google to have the apps removed. Avast named the adware TsSdk because the term was found in the first version of the adware," the cybersecurity firm said in a statement.

The adware applications are linked together by the use of third-party Android libraries which bypass the background service restrictions present in newer versions of the operating system (OS).

Although the bypassing itself is not explicitly forbidden on the Play Store, the cybersecurity firm identified it as "Android: Agent-SEB [PUP]", because apps using these libraries waste the user's battery and make the device slower.

The applications use the libraries to continuously display more and more ads to the user, going against Play Store rules.