in France sms advertissement (=spam) must include the key word "STOP SMS" with a phone number to unsuscribe from the spam list.
This Tasker project check of each received sms the presence of the "STOP SMS" keyword and grab the associated phone number (thanks to AutoTools regex).
Then it display a notification with the content of the message and a button to directly send the "STOP" message to the corresponding number (in the background)
As I don't receive much spam sms anymore, I couldn't test it with so much sms format, please let me know if you receive an sms with an incompatible format so I could improve the project !
Send "STOP SMS" to sms spam 1.0
Display a notification with a button to automatically send the "STOP" message for spam SMS