It is quite startling to find that on an average during the last four years, more than 87% of Android devices were vulnerable to attacks from malicious applications. The result is the outcome of a study conducted by University of Cambridge researchers. According to the report most of the handset manufactures fail to offer regular security updates to Android users. It is to be noted that LG, Motorola and devices under Google Nexus brand are better in this respect You can see the detailed summary on the site called Androidvulnerabilities.
The study was partly funded by Google itself. Google will use these findings to make Android a stronger OS.