Unless your iPad has been jailbroken, it's highly unlikely you have to worry about malware. As of February 2014, there is no known malware that can infect an iOS device that hasn't been jailbroken. However, this doesn't mean there won't be malware in the future. Whether or not your iPad has been jailbroken, you can clean it of any bad data by restoring it.

Restoring an iPad

To restore an iPad, connect it to a computer running the latest version of iTunes. After connecting the iPad to the computer with its USB cable, click the "iPad" button in iTunes and then click the "Restore iPad" button located on the Summary tab. The onscreen instructions lead you through the restore process. When the restore is complete, your iPad has been returned to its original factory condition. All your data and files -- along with any malware -- has been removed.