Unauthorised apps and app stores are contributing to a spike in mobile fraud, a media agency warns. "There are hundreds of thousands of apps and mobile services claiming to offer secure shopping portals or games or entertainment, and a significant percentage of these are actually designed to steal credit-card information, banking details and hard-earned cash," MediaWeb's Chad Fichardt said.Citing research by RiskIQ that showed how malicious mobile apps in Google Play had spiked nearly 400% last year, he said new research found there were thousands of unauthorised apps and app stores that referenced high-level brands. Of these 17% were blacklisted as they had failed a virus scan or linked users to a known source of malware.Users need to place protections onto mobile devices to prevent them being accessed, he said.Mel Gischen, marketing manager at electronic payment provider PayU, said: "Not having a back-up or a remote wipe system or placing password protection on a device means that the user may as well walk up to the nearest person on the street and hand them their credit card, login details and a shopping list."It's worth adding an additional layer of protection by using encryption software on all mobile devices as this will instantly slam up a barrier against a quick hack."Then ensure that remote wiping is activated - most modern devices allow for this - and delete all sensitive information the moment the device goes missing."Other options for protecting and even retrieving, the mobile phone are GPS tracking through services such as Find my Phone and Lock Screen Contact Info where people can see a name and alternative number and use that to return the smartphone if lost, not stolen. ..