I don't save these essential things on a PC. They are on unconnected drives that are kept in a safe place. 1000 times more difficult to lay your hand on then hacking the cloud. Passwords, log ins and source code are never on my PC's. I have a seperate PC for trading.
Only CosmosDB was affected, and CosmosDB already had a terrible reputation internally in the Azure organization... Do you love MongoDB, but wish it was slower, more expensive, and even less reliable? Then CosmosDB may be the database for you!
But your trading PC must be going online. Are you saying your compiled versions are in your trading PC? That helps but compiled code isn't a magic solution either. I don't keep the source in the cloud either for this exact reason and files I deem critical are encrypted. That said, a minimal cloud machine with a firewall and ports closed (only SSH + trading platofrm) is very safe. For example if your live trading machine is running Windows, it's already quite vulnerable.
Is a home Linux or Windows machine with firewall and all ports (except for platform) closed/stealthed anymore vulnerable than a cloud based one?
Probably less vulnerable in that you're the only one with physical access. Then again most cloud providers have additional security measures as far as I know, stuff like limiting SSH password attacks from the same IP. A home PC running Windows is more vulnerable than a cloud VPS running Linux IMHO. I don't hold Microsoft products in high regard when it comes to security.
@d08 Thanks. Im not very tech savvy, could you advise me on what else could be done to improve security of automated trading system? I was thinking about setup of two PCs: one (A) connected to internet, another (B) connected to A by LAN or parralel port, communicating with each other by Winsock or whatever. A gets data, sends to B to analyze and receives orders back from B to send to broker. Both A and B are behind firewalls and all ports except one are closed. Would this setup add any more security than just doing it all on a single pc?