Been getting calls at my office from this number.  We're in CT, and these calls come in at 5:30am (when no one is the office).  They stay on the line long enough to go through our automated prompts and get dumped into voicemail, where they leave 10-20 seconds of a blank voicemail message.  We've been getting about 3 a day since Saturday the 4th of January (2014).