Things To Check First

In users home folder check bash_history for commands/passwords, etc:

cat .bash_history

-l will list the allowed and forbidden commands for the invoking user:

sudo -l
Matching Defaults entries for takis on tenten:
    env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
User takis may run the following commands on tenten:
    (ALL : ALL) ALL
    (ALL) NOPASSWD: /bin/uckin