MrSlosh is correct guys. The recent events are unfortunate. The way I see it, we were hit with two attacks on NYC.
#1 The 51% - Someone timed this right, pre-fork. The fork was intended to update the code to minimize the effects of such and attack.
#2 The replacement of the GitHub releases. I'd have to go back to find it now but NYC was not the only repo on GitHub to suffer from this attack. Other Repos were also replaced with malicious binaries.
Both these seem to hit around the same time but I don't think it was the same attacker. Again, just my opinion.
We have hardened the GitHub repo as best we can and we are post-fork so the updated code can help with the 51% problem.
Standard Internet advise, Check any downloaded binary before execution... Think "Trust No One" here. Verify the source, checksums, Anti-virus scan, exc.
The team has been working to get more mining pools to merge mine NYC to help raise the nethash rate and make 51% attacks more difficult.