Pfft. They're crater chains, three of them, two of which make the X. The Moon has crater chains as well. Nothing unnatural about that. Although, if you look up posts by erstwhile member craterchains, you'll see where such speculation can lead. How come nobody's made similar noise about the "smiley-face" craters on Mars?
I'd be more impressed if the X was made of two crossing trenches, with perfectly straight edges and meeting at 90-degree angles. At least then we'd know where to dig.
"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684