Considering the fact that there will be (most likely) hundreds of nodes, it is not something THAT easy to DDoS all of them, but in case something like that happens the answer is, yes. There is a possibility that they can see your IP (even though chances are not that high) and possibly make a DDoS attack. If you are really keen on running bitcoin nodes (or any altcoin nodes in particular) you can check out some cheap VPS providers and host your wallets on VPS's alternatively, VPN is your option.
Thanks. So DDOS is the only threat of running a full node?
I have to open some ports to run the node right? Would It make me an easy target for malware?
I don't feel comfortable to run them on a VPS since I want to store my coins there.
Yes, pretty much. Not much can happen besides that, all they see is your IP but that means if you have any vulnerable ports, you are a target for more than just DDoS, it's really, really, really RARE but it is possible.
You have to also open Bitcoin node's port 8333.