They called - it was silence at first, but after they started speaking in Bulgarian. They had a chance just to explain they are calling from a call company (no names, etc.?) add to ask if I make calls to Bulgaria. I did not reply... This looks like a new Bulgarian service is looking for clients...
I got a call from this number but didn't respond. Then I decided to call back, and a bulgarian lady answered saying: "Dobur den!", meaning "good day!", then I hung up. I guess I have to call back again and ask them why did they call...