OSINT: Investigating SMS headers | India
TRAI has mandates registration of SMS marketing companies that provide services for tele-marketing. Lets analyze a Sample SMS header:
First Two Characters represent Service Provider and Circle / Origin Details
Ex. If you have received message from VM-AXISDT, it shows, Vodafone Idea is Operator and Service Area is Mumbai.
Details of the same is mentioned in the below document Detail_Header_Prefixes_16062020_0.pdf (trai.gov.in)
HEADER ANALYSIS
Since TRAI has mandated to register the headers for telemarketers, registration is mandatory. All registered entities list is found here: List of all headers and unique headers (publish)12–6–2020 (trai.gov.in)
In our case, SMS came from AXISDT, which on searching is registered by Axis Securities Limited.
If header is not registered with TRAI, SMS will not be delivered as operators have implemented DLT to filter out unregistered SMS headers.
How to use this Knowledge?
- In case someone is sending anonymous messages from free messaging platform, it is easy to identify the entity or telemarketing company used to send message.
- These companies can be contacted directly. Typically these companies save history of SMS send from their platforms so adversary can be caught.
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