vboxuser is not in the sudoers file .This incident will be reported!Enable sudo in Ubuntu -RESOLVED

Here are the steps to resolve the issue,

Step 1:

Change to root user using su root command and enter password

Step 2:

Install sudo package using apt-get install sudo -y

Step 3:

add vboxuser to sudo group

Step 4:

Change permissions of /etc/sudoers

Step 5:

Reboot the machine using command reboot

Step 6:

Login again using vboxuser

Step 7:

Try to login as root user using sudo su command

Hurray It’s success !!! Successfully able to do sudo login using vboxuser.