4) Stick to the Official Android Market for Apps
It's a good idea to be very selective about where you download your Android mobile applications. In fact, I suggest only downloading applications from Google's Android Market, even though the whole DroidDream situation proves the official Android Market is not 100 percent free of malware and other harmful apps. (Following the DroidDream debacle, Google did, however, vow to bolster Android Marketplace security.)
Every once and a while, I'll download an Android app from a source other than the Android Market, but I'm always aware of the potential danger, and I always use some type of antivirus scanner after the download to help ensure security -- more on Android antivirus coming up in the next section.
As a rule of thumb, it's a wise idea to get your Android software directly from Google's Android Market.
5) Google Android Antivirus
A good mobile antivirus app scans new Android software downloads for obvious signs of tomfoolery, such as strange permissions- or download-requests. And a number of free and commercial, or paid, Android antivirus apps are currently available in the Android Market.
I can't personally vouch for the effectiveness of them all, but in general, running one of the more popular antivirus apps is better than not running any antivirus at all. The app I've used most is Lookout Mobile Security. Lookout is available as a free download, with a basic antivirus scanner, Find-My-Phone features to help locate lost or stolen devices and backup/restore options. You can also upgrade Lookout for more in-depth security features, but the free version should provide basic protection for average users.
Another free antivirus option is the aptly named Antivirus Free app.
Even if you choose not to constantly run an Android antivirus application, it's a good idea to download one and scan your device occasionally for potentially harmful apps.
6) Android Wireless Connectivity and Security
In general, it's a wise idea to disable any and all unused wireless-connection options on your Android smartphone. In other words, you should turn off your Wi-Fi when you leave home and won't be in range of another Wi-Fi network for the day. When you're done using that Bluetooth headset in the car, turn off Bluetooth. Doing so will not only conserve battery life, it'll reduce the risk of malicious parties detecting, or even connecting to, your device without your knowledge.
In addition, you should also disable your Wi-Fi auto connect option -- if your device has such an option -- to ensure you don't automatically connect to a public Wi-Fi hotspot, through which a Bad Guy could access your device data. Turn off Wi-Fi auto connect by opening up your Android Settings menu, then choosing Wireless & Networks and next, Wi-Fi Settings. If your device has a Wi-Fi auto connect option, you should see it listed here. Uncheck the auto connect box to turn off this functionality.
On the Wireless & Networks settings page, you'll also see a Bluetooth Settings option. Open up your Bluetooth Settings and turn Bluetooth on if it's not already. Then click the Device Name option and change your Android's name to something unique and specific to you. This will reduce confusion in the future, should you attempt to connect your smartphone to another device via Bluetooth.
If your Android device supports mobile hotspot features, you'll want to secure your personal network. First, again open up your Wireless & Networks settings and then scroll down to and select Mobile Hotspot. Next, turn on your Wi-Fi hotspot feature and click the Wi-Fi Hotspot Settings settings menu.
Once the hotspot features are activated, your Wi-Fi Hotspot Settings page should show an option to Configure Wi-Fi Hotspot. Open up this menu, assign a new, unique name to your network, choose WPA2 PSK security from the dropdown menu and then assign a password to your network. Save your changes, and your Wi-Fi hotspot is now secure.
It's a good practice to turn off you Wi-Fi hotspot when not in use, so unauthorized parties cannot employ your network, eating up you monthly data allotment and/or accessing your device information.