Articles like these
http://www.pcworld.com/article/2953484/android/google-pledges-a-speedy-stagefright-security-fix-for-nexus-devices.html#tk.rss_all

highlight a bigger issue. There are lots of inconsistencies in the Android phone economy. Truth be told. Apple had its own crisis a couple of month ago. iPhone users could have their devices shut down (but not hacked) by rogue text messages. Android phones outsell iPhones by a factor of about 2 to 1 on a global scale. However, keep in mind that there is not one Android phone. There are dozens if not hundreds of current models from numerous manufacturers. Quality varies….. considerably.

Although I personally use an iPhone (iPhone 6), i am not trying to steer anyone away from buying an Android phone. If you are really tied into Google services, and don’t use a lot of Apple services (i.e. no purchased movies or TV shows from iTunes, no Apple TV ) — an Android phone would be an appropriate choice.

However, there is one key difference between Android phones and iPhones. When there is a major flaw, Apple can push an update out directly to the customer’s phone. With Android, its not that easy. In nearly all cases, the manufacturer must get approval from the carrier. One exception is the Nexus line of phones sold directly by Google. Some manufacturers have better reputations than others in terms of pushing out updates.
In terms of timely updates, I would rank key manufacturers in this order
1. Google – Nexus phones
2. One Plus (and independent manufacturer targeting the US market)
3. Motorola
4. Samsung

I really cant think of other Android phone makers that are worthy of consideration. FYI, all Android phones should have anti-virus software installed. My favorite is Lookout. They have a free version and a paid option.

Since Android phones become obsolete more quickly, its important to but an Android phone within the first 12 months of release and ideally the first 6 months.

I am definitely not trying to steer anyone away from Android. For some people who want a cheaper smartphone, and are unsure of making a cost commitment to the iPhone, Android is the only option. As I have mentioned before Motorola has some excellent sub $200 (true cost) phones.

Shop wisely!