Ubuntu 24.04 terminal session: hardening a bug bounty VPS

apt-get update -qq && apt-get install -y -qq dnsmasq 2>/dev/null; systemctl stop systemd-resolved 2>/dev/null; systemctl disable systemd-resolved 2>/dev/null; echo "nameserver 127.0.0.1" > /etc/resolv.conf; chattr +i /etc/resolv.conf 2>/dev/null; printf '%s\n' 'bind-interfaces' 'interface=lo' 'no-resolv' 'server=1.1.1.1' 'server=8.8.8.8' 'cache-size=100000' 'neg-ttl=3600' 'dns-forward-max=10000' > /etc/dnsmasq.conf; systemctl restart dnsmasq 2>/dev/null; printf '%s\n' 'net.ipv4.ip_local_port_range=1024 65535' 'net.ipv4.tcp_tw_reuse=1' 'fs.file-max=999999999' 'net.core.somaxconn=65535' 'net.core.netdev_max_backlog=100000' > /etc/sysctl.d/99-bugbounty.conf; sysctl -p /etc/sysctl.d/99-bugbounty.conf 2>/dev/null; printf '%s\n' '* soft nofile 999999999' '* hard nofile 999999999' > /etc/security/limits.d/99-bugbounty.conf; fallocate -l 4G /swapfile 2>/dev/null && chmod 600 /swapfile && mkswap /swapfile 2>/dev/null && swapon /swapfile 2>/dev/null && echo "/swapfile none swap sw 0 0" >> /etc/fstab; echo "===== VPS HARDENED FOR 100+ SCANS ====="