Every server connected to the internet is constantly being attacked with brute force login attempts, software exploits, email spam and more. It is the dirty laundry all IT Security or anyone who manages there own website or server knows. With the extent of dark nets, bot nets and abused proxies this activity runs amuck and pretty much unstoppable. The only thing we can really do is just make sure our software is up to date and passwords are strong.
Just the other day one of my reseller hosting servers located in Germany was terminated and another at Hostgator was suspended. I was told that my wordpress sites were using too much CPU from the server. Looking at the log snapshot sent by Hostgator indicated that all of the usage came from the wp-admin.php script. Was this not obvious to them? Someone was trying to brute force open the wordpress admin. After informing Hostgator that this was not my fault unless they didn’t think I should be using the most popular blog software they were quick to start blocking IP’s coming in. The German company (who I won’t name) said this was beyond the capabilities and that there policy was to take down any website that gets attacked…WTF? Ya I will be ditching them next week, any policy like that which penalizes the website owner for an attack rather than simply blocking the attacking IP’s is bullshit.
The German company told me as did Hostgator the attacks were all coming from China and the Ukraine. On my own managed dedicated boxes I have blocked these countries completely, along with other countries that have originated some scams and abuse such as Nigeria.
If you manage a linux server this is really easy here is how you can block nearly all the traffic from specific countries from coming into your website.
First get and install Advanced Policy Firewall (APF) https://www.rfxn.com/projects/advanced-policy-firewall/
Once you have that installed and configured properly according to the documentation login to your shell and find the apf folder usually at /etc/apf and edit the file deny_hosts.rules
Goto wizcrafts.net and find the APF IP lists for the desired countries. Here is some quick links
South America: http://www.wizcrafts.net/lacnic-iptables-blocklist.html
Other Exploited Networks: http://www.wizcrafts.net/exploited-servers-iptables-blocklist.html
Copy and paste these lists into the deny_hosts.rules and then save it.
Restart APF by #apf –r
If you find other IP’s in your logs that you want to block you can just edit this file and add those IP numbers to the list and restart APF.
These lists of IP’s change regularly so you may want to once a month go back and update it.
If your internet business for your server has nothing to do with these other countries there is no real reason not to block them using this or another method.
If you have an IP# and your not sure what country it is originating from, use http://www.infosniper.net/ to look it up.