Watch out for an assumed false detection with some AV apps when updating the blockchain in Bitcoin-Qt or bitcoind.
Over at the Github there is a thread about Silly-218.
SAV reported bitcoind infected w Silly.218, crashed bitcoind (likely false positive) #4069
https://github.com/bitcoin/bitcoin/issues/4069My thoughts:
If you get hit by "Silly-218" and your AV app deletes that file detected, as part of your blockchain, one will have to re-download the entire blockchain if one hasn't already got it backed up elsewhere. Norton zapped it in my case, and that part of the blockchain with it. Oops...
Fortunately for myself I had it backed up elsewhere so I only had to re-download a couple of weeks worth of the blockchain. Upon re-downloading/updating the blockchain I had no more run-in's with Silly-218 so it's merely a random thing.
Another PC of mine running Bitcoin-Qt hasn't had any problems, maybe it's because Kaspersky is on it, or I have just been fortunate so far.
After re-downloading the last two weeks of the blockchain on the Norton PC I didn't get hit again so it's a hit or miss thing obviously.
Caveat emptor