Apples over-the-top messaging service iMessage is responsible for 30 per cent of all mobile spam messages, according to statistics from security company Cloudmark.

The iMessage system enables users to send texts phone-to-phone without paying mobile carrier fees, and spans across the iPad, iPhone and Apples desktop systems. However, it is this versitility that has made it so vulnerable to spam messaging.

Speaking to Wired, Tom Landesman of Cloudmark explained that the combination of desktop and mobile programming makes it easier for spam creators to write a Mac OS script that sends messages to all types of devices at high speed. “Its almost like a spammers dream,” said Landesman. “With four lines of code, using Apple scripts, you can tell your Mac machine to send messages to whoever they want.”

A year ago, spam through iMessage was virtually unheard of, but now it accounts for over 30 per cent of all mobile spam messages, partially due to one particularly aggressive campaign attempting to sell imitation designer handbags and sunglasses.

Because iMessage links phone numbers and email addresses, spammers only require one of these to be able to message an account, and because the messages travel on Apples network, they are beyond mobile carriers powers to regulate. While Apple has rate-limited how quickly iMessage accounts can send and receive messages, there has been little else in the way of a response to the growing spam, and since registering with iMessage can be done using any email account, spammers can send huge volumes in relatively short periods.