I also study network security and this is useful until I know crypto, where blockchain is specifically designed for anti-hacking because they need proof of each block to be said to be valid. but hacking on the exchange, especially centralization is utilizing the API key loopholes so that hackers are able to access user funds on the exchange server, so also in DEX with DNS techniques they are reportedly also able to provide losses to users, so my conclusion is that there is no 100% safe on computer networks