Samsung has admitted an internal testing mistake was to blame for the company sending a notification out to a large number of users that simply read ‘1’, and appeared to be from the company’s Find My Mobile app.
Yonhap News in Korea reported that Samsung explained the error in its Samsung Members app, saying “This is a message sent wrong during the internal test, there is no effect on the customer’s smartphone”.

Some users were worried their phone had been hacked in some way after receiving the notification. It was most likely meant to be an internal test on the location-based first party app that was pushed out to many users accidentally.
As the world’s most popular smartphone manufacturer Samsung can’t really hide when it makes mistakes like this, though on the face of things it isn’t too harmful.