https://help.ubuntu.com/community/RootSudo#Misconceptions
> Any user who uses su or sudo must be considered to be a privileged user.
> If that user's account is compromised by an attacker, the attacker can also gain root privileges the next time the user does so.
> The user account is the weak link in this chain, and so must be protected with the same care as root.

sudoとsuの違いの話の中でだけど一応UbuntuのWikiでも指摘されてるね
sudo使える管理専用のユーザーとsudo使えない普段使い用ユーザー2つ作るのがベストって事かな…
ﾒﾝﾄﾞｸｻｲ(´・ω・｀)