The last year has been a phenomenal one for the Android ecosystem. Device activations grew 250% year-on-year, and the total number of app downloads from Android Market topped 11 billion. As the platform continues to grow, we’re focused on bringing you the best new features and innovations - including in security.

Adding a new layer to Android security
Today we’re revealing a service we’ve developed, codenamed Bouncer, which provides automated scanning of Android Market for potentially malicious software without disrupting the user experience of Android Market or requiring developers to go through an application approval process.

The service performs a set of analyses on new applications, applications already in Android Market, and developer accounts. Here’s how it works: once an application is uploaded, the service immediately starts analyzing it for known malware, spyware and trojans. It also looks for behaviors that indicate an application might be misbehaving, and compares it against previously analyzed apps to detect possible red flags. We actually run every application on Google’s cloud infrastructure and simulate how it will run on an Android device to look for hidden, malicious behavior. We also analyze new developer accounts to help prevent malicious and repeat-offending developers from coming back.

Android malware downloads are decreasing
The service has been looking for malicious apps in Market for a while now, and between the first and second halves of 2011, we saw a 40% decrease in the number of potentially-malicious downloads from Android Market. This drop occurred at the same time that companies who market and sell anti-malware and security software have been reporting that malicious applications are on the rise. While it’s not possible to prevent bad people from building malware, the most important measurement is whether those bad applications are being installed from Android Market - and we know the rate is declining significantly.

Android makes malware less potent
In addition to using new services to help prevent malware, we designed Android from the beginning to make mobile malware less disruptive. In the PC model, malware has more potential to misuse your information. We learned from this approach, designing Android for Internet-connected devices. Some of Android’s core security features are:

• Sandboxing: The Android platform uses a technique called “sandboxing” to put virtual walls between applications and other software on the device. So, if you download a malicious application, it can't access data on other parts of your phone and its potential harm is drastically limited.
• Permissions: Android provides a permission system to help you understand the capabilities of the apps you install, and manage your own preferences. That way, if you see a game unnecessarily requests permission to send SMS, for example, you don’t need to install it.
• Malware removal: Android is designed to prevent malware from modifying the platform or hiding from you, so it can be easily removed if your device is affected. Android Market also has the capability of remotely removing malware from your phone or tablet, if required.

No security approach is foolproof, and added scrutiny can often lead to important improvements. Our systems are getting better at detecting and eliminating malware every day, and we continue to invite the community to work with us to keep Android safe.

Source:http://googlemobile.blogspot.com/2012/02/android-and-security.html