Second link TLDR: if you create a bitcoin trojan, you can steal bitcoins. Excerpt: "The attacker must first create a compromised version of ECDSA". Nothing worth fretting over.
900+ words, and I recommend reading them all.
My favorite excerpt:
Both Verbücheln and Pustogarov say that the most likely way for such an attack to be mounted would be through dedicated wallet services running proprietary software. Devices designed specifically for secure cold-storage of coins, for example, would be prime candidates for this sort of attack.
Stealing your digital currency right off the blockchain - they don't even need to get to your computer, much less your wallet!
Edit: I've added some additional recommendations to my "
The Most Secure, Least Hassle, Security Option" I posted earlier. Nothing's perfect, and nothing's perfectly safe - you can only do your best, and
the last line of defense is NOT having all your eggs in the same basket.