Can you explain your concerns in more detail? A "hack attack" could mean just about anything, but we are always working on making the Terracoin wallet more secure. We will be adding more features that increase security with each release, and have even thought about adding 2FA to the wallet in the future.
As for the DDOS attack fear, Terracoin is decentralized including the masternode layer. The more masternodes there are, the less likely for a DDOS attack to work. Also most VPS servers now come with DDOS attack mitigation so a DDOS attack becomes less and less likely as time passes.