Symbian Mosquitos Trojan was deliberate

The so called Trojan dialer that was recently found in illegal warez copies of the Ojom Mosquito game was deliberately hidden in the code by software engineers as a security feature. When a cracked or stolen copy of Mosquito is installed on your Symbian Series 60 smartphone, a hidden dialer would send a text message to a premium number resulting in a £1.50 charge to your phone every time the game is played.

When news first hit about this problem, many people assumed it was a third party virus imbedded in the game by the hackers who cracked the software. Ojom has removed the premium number from service as well as the phone home functionality from current legal software versions on their website.