Category Security

Attacking Attackers to Protect a WordPress Website

I have previously demonstrated how to protect wp-admin and wp-login files in word-press website.
I wanted to do more. Something like: Attacking those attackers.

What Crashes Browsers?
What crashes applications is what hackers call: Buffer Overflow Exploit. Hackers use them to take control of applications/browsers to gain full system access later on. More about buffer-overflows here.
We are not interested to take control of the attacker’s system; Although that will be very ‘cool’ – maybe the next stage? 😉
We are more interested to stop them i.e: Crash their browsers, fuzzing and brute-force tools.

Results.
Amazingly I was able to reduce attacks from 4000~ to around 70 only!

What is happening behind the scenes?

Read More

HashClipper – The Fastest Online NTLM Hash Cracker

Inspiration
I simply wanted to create my own -fast- NTLM hash cracker because the other ones online are ether dead, not maintained, obsolete, or the worst one: a rip off.
Of course the greatest inspiration was this:

Intro
NTLM is the hash mechanism used in Windows. It’s usually what a hacker want to retrieve as soon as he/she gets into the system.
Cracking NTLM hashes can also help normal users or administrators to retrieve a password without having to reset it.
Please refer to

Read More

How Is Ubuntu Spying on You and What to do about it

Intro
I was lately surprised by my new ‘Ubuntu Server’ computer connecting back to a strange IP address: 91.189.92.11 on port 443! I immediately started investigating the case and did a whois lookup on the IP address to discover that the IP points to this domain productsearch.ubuntu.com – a page that will display a 403 Forbidden Error.

What is productsearch.ubuntu.com?
So apparently according to this website: If you’re an Ubuntu user and you’re using the default settings, each time you start typing in Dash (to open an application or search for a file on your computer), your search terms get sent to a variety of third parties, some of which advertise to you. Ubuntu should protect user privacy by default. Since it doesn’t, you can use the code to the left to disable the parts of Ubuntu which are invasive to your privacy.

You can also read more about Ubuntu 3rd parties: http://www.ubuntu.com/privacy-policy/third-parties

Read More

Blocking Tor Traffic to Your Server

You’ve seen before how I got targeted by thousands of brute force attempts and how I mitigated the attacks earlier in this post; however, I wanted to do something better and more efficient. A filter at the firewall to block all these attempts from even establishing a basic TCP connection with the HTTP server.

The Problem
One major problem is that these attempts were not coming from a single IP address. Attackers will use TOR to hide themselves and to have different IPs to over-come the first obstacles that is: blocking the attacker’s source IP address.

Read More

Lately this blog has been targeted by many attackers varying from brute force attacks to D-DOS. Although I couldn’t do much about DDOS (servers provider takes care of that), I was able to mitigate the brute forcing attacks on my wordpress. I’ve been using this trick for a while and it keeps bad guys away from my wp sensitive pages.

First let me share with you a snippet from my logs. (I know you love these 😛 )

Yep that is a 4167 attempts to penetrate wp-login.php form. Fortunately I know this was coming so after installation I simply created a filter using Apache .htaccess to filter out all connection to wp-login.php and wp-admin/ except the one coming from my IP address!

Read More

Disable SSH Password Authentication and Use PublicKey Authentication Instead

I use my own VPS for hosting this website. Hence I get attacked on daily bases. The last time I checked the logs I had more than 2500 attempts to break into my SSH server from around the world. These attackers are mostly opportunistic I believe (or I hope!)

Since the number was very high, I decided to disable password auth and keep publickey auth only. It’s pretty simple.

Step 0: You already have public/private key set and configured in your ssh server and client.

Then you want to edit SHHd config file under:

First make sure you enable public-key authentication or you will lock yourself out!

Read More