The first trojan has been found on the Apple App Store, researchers say.
The 'Find and Call' app, also on Android's app store, uploads a user's phonebook and GPS coordinates to a remote server and sends spam SMSes with a URL to contacts.
Users were asked to register thier email address and mobile phone number with the app and to ‘find friends in a phone book'.
Kaspersky researcher Denis Maslennikov said the spam SMSes contain the victims' phone number in the ‘from' field which would appear as a trusted source.
The App's creator told AppleInsider.ru that the system was in beta-testing. "In result of failure of one of the components there is a spontaneous sending of inviting SMS messages. This bug is in process of fixing. SMS are sent by the system, that is why it won't affect your mobile account.”
Apple and Google pulled the app.
Sophos director of technology strategy James Lyne said it was not the most insidious payload.
“There are other apps with superior techniques, some by accident and some intentional, but this does show that things are possible and we should not rest on our laurels about smartphone security. However the application checking process needs to be more transparent."