Other than clumping issues, I've never heard of DME going bad. I guess it could, but it's never had the chance around here.
Even if it had gone "bad," it wouldn't be due to bacterial or wild yeast contamination. However, the normal boil you do for starters should take care of any issue.
In other words, you ought to be just fine.
Beer is good for anything from hot dogs to heartache.
Drinking Frog Brewery, est. 1993