Network swiss army knife
There’s no better way to say it, netcat is SOO useful, and there is an encrypted variation… cryptcat, you can do quite a few interesting and useful things VERY easily with these two utilities. (*It’s one of the utilities I used to image a live running system to a file on a network server.) The source is available from the previous two links. There are binaries for windows for both netcat and cryptcat available here, but with all such tools you should be wary of where a precompiled binary comes from.