Malicious adware (madware) was present in 24% of Google play apps in the six months to June 2013, compared to the 15% recorded across the whole of 2012, according to a report from Symantec.

According to the report, most of the madware was aimed at Google’s Android operating system and used aggressive ad libraries to attack the devices.

The report claims that over 50% of the 65 ad libraries present can be categorised under the aggressive libraries category.

Symantec said in the report that the security risks are expected to grow in the Android applications.

"There was a large increase in the number of malicious APKs in the middle of 2012 and again in the second quarter of 2013," the company added.

"The presence of madware on Google Play has grown from 2011 to 2012 and again in the first half of 2013, while the vast majority of third-party app stores host an even greater presence of madware and malware."

"By the end of this year, we can expect one in four free apps available on Google Play to contain madware."

The report revealed that the presence of madware in each app category varied on Google Play and on third-party app stores and the apps from the Personalisation, Libraries and Demos segments were having the most madware.

The third-party app stores are said to contain more security risks while just 11% of the total third-party app stores had a lower amount of madware compared to Google Play.