Sending a class 0 or flash SMS with the iPhone

A class 0 SMS (or Flash SMS) is an SMS that is automatically opened and displayed on the recipient’s phone without being saved in the inbox. On Nokia phones and Blackberries there are usually an option to save a received flash SMS, but on iPhones there are only a big “Dismiss” button and best of all the sender’s number is not displayed! This means you can use this technique for much mischief…

On the left is an example of a Flash SMS received on an iPhone. As you can see there is no option to save it or view the sender’s number. On other phones the sender’s number is displayed.

You need a jailbroken iPhone for this to work. First read the page here:http://xsellize.com/topic/25209-flash-sms-on-iphone/
It shows you how to install Minicom from cydia and configure it to connect to /dev/tty.debug .
The post is informative but lacks three important pieces of information.

1. First step: mkdir /usr/etc
2. Before entering “at”, first press down and hold in spacebar until the cursor starts moving. You need to do this to “get the attention” of the /dev/tty.debug modem otherwise it’s just going to ignore everything you send it.
3. When crafting your Flash SMS using http://rednaxela.net/pdu.php , SMSC should be 0 and Receiver is the number of the person you’re sending the message to. Remember to set message class to 0.

Once the modem is responding to your commands in Minicom, simply enter the following:
AT+CMGF=0
AT+CMGS=(number from the site in the “Hex PDU message” column)
> (Paste the characters from the pdu site but do not press enter)
Press Ctrl+Z

That’s it. Enjoy!