In the last week of November 2012, we announced that a strong electrotelluric disturbance, which we judged to be a Seismic Electric Signal (SES) activity, was recorded at station Assiros located in Northern Greece. This disturbance was actually followed by an Mw5.8 earthquake on 8 January 2013 in North-Eastern Aegean Sea. Here we show that, by analyzing this SES activity and employing the natural time analysis of subsequent seismicity, we estimated the epicentral location, magnitude and occurrence time which are reasonably compatible with those of the Mw5.8 event.