Detection of Silent (Stealth) SMS Type 0 [$115 awarded]

Created by: SecUpwN

Law enforcement agencies are very often sending out so-called "silent SMS" (see this German article) which do not show up on a display of a target device, nor trigger any acoustical signal when received. But when they are delivered they generate a delivery receipt and, most importantly, are recorded in a data retention database together with the location of a mobile phone which received it. There's no need for an IMSI-Catcher then. Reliable detection of silent SMS will be crucial to the usefulness of AIMSICD.

A Silent SMS / Stealth SMS / Ping SMS is a Type0 SMS which is specified in GSM 03.40 as follows: "A short message type 0 indicates that the ME must acknowledge receipt of the short message but may discard its contents."

I have already contacted Michael (@SilentServices), the developer of the useful tool called HushSMS, which also enables its users to send out different types of SMS (including type Class 0, but without the location request). Check out his company Silent Services. I have bought his app a long time ago and am hoping he'll contribute some code snippets for detection of such SMS. Stay tuned.

The $115 bounty on this issue has been claimed at Bountysource.