What is oozing out of my house??

[Rumline]

Was outside cleaning our neighborhood's trash out of the back yard today when I noticed this black/brown stuff dripping down the siding. Anybody have any idea what this could be, or what I should do to investigate further?

This section of siding is under an overhang. As far as I know there are no pipes behind this wall. It can't have been there longer than a week or two but as my wife will remind me I'm not the most observant sometimes.