Kaspersky Labs has released a report claiming that the Android 2.3 Gingerbread is the most attacked OS by malware. Kaspersky more specifically names Android 2.3.6 as the major target for malware and trojan SMS software. The only redeeming statistics for Gingerbread is the malware mods over the last year have dropped from 14,923 to 9,130, showing a move in the right directing for malware detection. Kaspersky has also stated that the newer versions of Android have little to worry about right now when it comes to virus and security related attacks.
If you have Gingerbread on your device you may never run into a problem, although you can decrease your odds of a malicious attack by simply leaving installations from unknown sources turned off. If you must leave it on because you use something like the Amazon market for apps then you should make it a point to install an antivirus like Lookout Mobile Security.
While Android security has been an ongoing concern for those that want to switch to the popular OS the issue can be avoided. If you have had security issues in the past let us know what it was and how you came about it (if you know).