Who called from 3394991625

I've gotten at least two text messages from this number that just say "OK"

everytime my phone dies and i turn it back on i have a new message and all it says is "ok" so i would also very much like to know. it's been happening to me for the past 2 weeks or so

I got it 2.  On another site someone said it was geek squad from best buy

I received random texts of "ok" with every hour on the hour.
How can I stop.it?

Yup- definitely getting OK almost every hour...