Who called from 7074281494

Simple hanger-upper.   Called my cell phone, let it ring enough to hit my outgoing message, and left a blank 3 second moment of silence message.   It's gotta be a robo-dialer with a bad set of timing parameters.    With all the hackers out there, can't someone develop a computer virus to completely destroy these callers' equipment?

While the call listed an ID (Shaw, L) the name was unknown to me and they left no message.