You probably got someone's "server transfer" money. :) Oops.
Sometimes people will put up cheap enhancements with a character with no money, then jump to the "rich level 50 over on server X", they'll buy the cheap enhancement assuming it's their own and bamm, money transfered.
Sounds risky to do, but I've thought of doing that to transfer stuff from my villains to my heroes (which won't work of course because the markets are separate darn it).
Fortunately, having started a second account, transferring stuff is much, much easier than that. For people without two, it would be safer to just buy really expensive items on the market, put them in your base, have your other character pick them up and re-sell them for the same or lower price (or higher if you can manage it).
That was no intercepted transfer. I wated weeks for it to sell. Server transfers are always done with some item which has no bids and none for sale at the time.
