02-04-2018 03:27 PM - edited 02-04-2018 03:28 PM
Those SMS contain TAC that can authorise third party service to subscribe your number to paid services. http://community.digi.com.my/t5/Apps-Services/Third-Party-Charges-for-SMS-from-Content-Providers/ta-...
If you did not make an intended subscription, do not type these TAC into apps/websites that request for it.
Do watch out for any recently added apps that may have also triggered subscription to third party services. Also be careful in allow Messaging permission on your Android device, which allows app to read TAC from your SMS inbox.