How to identify a script sending spam through Postfix

How (step by step):

• Switch to a user with sudo rights
• Check the mail queue with command mailq
• The first column of the mail queue list shows unique mail ID's, pick one from an obvious spam email and copy it
• Check this email's details with command postcat -q using the unique mail ID you copied in place of
• Identify the line starting with "X-PHP-Originating-Script". This should show which script is generating the spam emails
• Remove the script, patch the website with latest security fixes and make sure folder and file permissions are secure
• Empty the mail queue with command postsuper -d ALL
• Check the mail queue again with command mailq to see if more emails are now generated. If the problem persists, repeat the above steps and see if you find other scripts causing you problems.

Source: http://frontmag.no/artikler/how-identify-script-sending-spam-through-postfix

Disable IPv6 in Ubuntu

Good when you don`t know much about stuff and don`t know how to configure IPv6 firewall.

Edit /etc/sysctl.conf

Paste to the end:

net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1

Run sysctl -p

After that if you check,

$ cat /proc/sys/net/ipv6/conf/all/disable_ipv6

You will get result as,

1

If you get result as 1, ipv6 disabled successfully.

Install MySQL Server in Ubuntu Without a Password prompt

debconf-set-selections <<< 'mysql-server-5.5 mysql-server/root_password password rootpass'

debconf-set-selections <<< 'mysql-server-5.5 mysql-server/root_password_again password rootpass'

apt-get update

apt-get -y install mysql-server-5.5