There have been some reports about a trojanized version of "Mosquitos" game for Symbian phones that secretly sends SMS messages to premium rate numbers.
We detect this case as Trojan.Mquito. Actually, it's not a trojanized version of the game, unlike many reports state. Turns out the hidden SMS functionality was put in the game from the beginning by the original manufacturer.
This functionality was supposed to be some kind of a copy-protecting technique, but it didn't work right and the whole functionality backfired.
According to the manufacturer, the premium rate contracts for the phone numbers have been terminated, so although old versions of the game still send hidden SMS messages, it only costs the nominal fee of sending the message itself.
Current versions of this game no longer have this hidden functionality, but "cracked" versions of Mosquitos still float in P2P network — and they still send these messages.