Before you automatically assume 'aliens', it's likely that these radio signals have an astronomical origin... we're just not quite sure what that could be as yet.
Some of the leading hypotheses for the cause of these repeating signals are highly-magnetic magnetars - a type of neutron star that's surrounded by energetic material. They could also be produced by young neutron stars that emit regular radio pulses as they spin.
Sources : http://www.sciencealert.com/we-just-picked-up-15-mysterious-radio-signals-from-a-distant-galaxy