Infected iOS?

I have an iPhone 4

Since installing iOS6 I’ve had problems like slow performance, frozen and crashing apps and a bizarre problem with the mic picking up environmental noise when the earbuds are used as a phone handsfree.

Voice Actions (From the developers of SIRI) is acting so weird it’s useless.

I use Perfect Browser (video out capable, rock!) to Internet a lot in case that’s how I picked up something.

The earbuds have been replaced.

I reboot often.

I’ve reset.

I’ve restored twice and warranteed the phone twice.

iOS 6.0.1 did not fix my problems.

Can iPhones even get a virus or another form of malicious code? Can the infection come back in a backed up app or file?

Before I call Apple again I’d like to get some real world perspective. Thank you in advance.

Suggestions to go with another make of device will be met with an eyeroll and bemused sigh.