I have enabled 2 step authentication on my outlook (Hotmail) email ID. 

On the last log in (26th August, 2013), it asked me for the code which i received as an SMS on my mobile number. 

I used that code for successful log in. After logging in, i started receiving the same code multiple times. At least 10 times on 26th, then a few times on 27th and again 4 times today. The code remains the same. And i receive the code in a particular time frame only (9 pm -11 pm - GMT + 5.30).

The code comes from these numbers-

+1 876-771-0055

+44 7624 815459

Is this some kind of an internal configuration error or a hacking attempt?

Regards,

Anuj