Anonymous message in my group message

[walkervela]

I was in a group message with a total of three people. (Including myself) I received a message that read "Sorry" and the number said it was from anonymous@anonymous. Neither of the other two people in the group message received or sent the message. Any ideas on where this came from and how it ended up in the group message? Any information would be greatly appreciated.

 

[casperes1996]

Sounds freaky and scary, man

 

[Mr_Brightside_@]

Screenshot pls