I am facing these problems , call dropping , touch problem etc let me know about the solution

There are no viruses, or any other kind of malware, known to be able to infect an iPhone, unless it has been jailbroken.

First, try resetting your device. Press and hold both the home button and the sleep/wake button for about 10 seconds, until the screen turns off. Ignore the slider that will appear. Release the buttons, then press and hold the sleep/wake button until the Apple logo appears. This is the equivalent of a reboot, and should not affect your data or apps.

If that doesn't help, try restoring your device from backups, and if that doesn't help, restore it to factory settings (ie, do not restore a backup). See:

http://support.apple.com/kb/ht1414

If none of that helps, the issue is caused by some kind of hardware problem, and the device will need to be repaired or (more likely) replaced.