Hmm, not sure if its malope trifida, click on fifth image in this link

http://www.alibaba.com/product-detail/Chinese-Mallow-Malope-trifida-Flower-seeds_60294891634.html

or a version of Malva sylvestris, which doesn't seem quite as lilac coloured as the one in your pic, more of a a pinky purple than lilac.

Now there is another one that is more pinky purple than this one. So I wonder!

I grew some mallow plants a few years ago called 'halo'. I wonder if these are disturbed seed from those.

Probably - the one in the pic is a lovely colour!