Is that Spam in your pocket, or are you just using iMessage?

In a “not good news story,” it was announced by security and anti-spam company Cloudmark that Apple’s iMessage now accounts for more than 30 percent of all mobile spam messages.

Speaking to the media, Cloudmark employee Tom Landesman said that a year ago he had never seen an iMessage spam, but because of an aggressive campaign by a junk mailer, it now accounts for a full third and more of mobile spam messages.

“It’s almost like a spammer’s dream. With four lines of code, using Apple scripts, you can tell your Mac machine to send a message to whoever (you) want.”

Why the iMessage attack?

“iMessage is particularly enticing to spammers because they can easily use a Mac to send messages,” according to iClarified. “All they need is an email address and the recipient will likely get the message on their phones, computers, and tablets.”

Worse yet, Apple’s desktop client immediately tells a user if an entered number or email is registered with iMessage.

“That lets spammers quickly generate lists of verified iMessage users,” says the report. “Furthermore, some users have iMessage set to automatically report whether a message has been read or not.”

Landesman says that Apple’s switch to rate-limiting messages (which it didn’t used to do) is weak defense against spammers who just register for additional free accounts.