The amount of malware on mobile devices is quickly growing, putting many users at risk, but these at risk users are mainly on the Android platform which is the target of 91.3% of all smartphone malware, according to F-Secure. 

iOS is much safer than Android, with attacks much more difficult to implement, thanks to Apple's developer program. 

According to F-Secure's latest report, the number of active mobile threat families and variants on Android has risen to 136 out of 149 threats, this is up from 96 out of 100 earlier this year, and 49 out of 74 known threats at the end of 2012. It was after news that threats had risen to 96 out of 100 that Phil Schiller, Apple's head of worldwide marketing, decided to tweet (a very rare occasion) a link to the F-Secure report, saying: "Be safe out there."

This means Android is the target of 91.3% of all malware activity, this number has risen massively from 79% in 2012. The remaining percentage of threats are related to Symbian, which is an open source platform used in certain Nokia smartphones. Apple's iOS, Microsoft's Windows Phone and Blackberry are free of any malicious activity, making them the safest operating systems out there, according to the F-Secure report.  

Read next: How to remove iPhone viruses

Why isn’t Android safe? 

Android users are singled out by scammers, who direct them to job offers and services and prompt them to update certain components, such as Adobe Flash, explains Apple Insider. The malware is granted access to the user's phone, and then installs code to either intercept personal information, such as bank details.

Even legitimate apps from Apple’s App Store are limited as to what information they can get from the users phone. 

Android's malware largely targets users who haven't got the latest software version. It may be the case that a update is available that would protect the device, but this update may not be available for older Android devices, giving hackers and malware authors the edge.

People who rarely download apps are also affected, as malware is now sent via email. In the F-Secure report, Sean Sullivan, a Security Advisor at F-Secure stated: “I’ll put it this way: Until now, I haven’t worried about my mother with her Android because she’s not into apps. Now I have reason to worry because with cases like Stels, Android malware is also being distributed via spam, and my mother checks her email from her phone.” 

Users on any mobile platform can receive such emails which direct them to dangerous malware websites. Of course iOS users (at least those who haven’t jailbroken their phones) cannot download apps from any site other than the App Store. Apple is also quick to distribute updates to protect users where necessary, frustrating any attempts at writing iOS malware. 

Android is an open source platform, whilst Apple's iOS is strictly controlled by limiting what apps can do on iDevices and what information they can access.