iPhone 4S virus?

I Have an iPhone 4S and recently I was on my twitter when someone sent me something that I stupidly opened, it turned out to be a virus and sent messages to all my friends so I deleted twitter and re installed it, then I started getting text messages, weird ones saying I won blah blah blah an I never give my number out, so I cleared my cookies and alot of my stuff and restarted my phone? But none of that has helped.... So I'm pretty positive I have a virus on my phone... Help?