Archive for the 'Intrusion Prevention' Category

DoS TCP SYN Attack Mitigation

Friday, August 21st, 2009

TCP SYN flooding is often used in conjunction with IP spoofing. The main aim of a TCP SYN flood is to send a TCP SYN packet to a host inside your network from a spoofed IP address. The TCP SYN ACK is then sent to a machine that is not expecting one, or a machine [...]

Mitigating SubSeven attacks

Thursday, August 20th, 2009

SubSeven – aka: Sub7 and Sub7Server is a backdoor program, in the form of a Trojan, used mostly for causing trouble on computer networks. It can be used for simple attacks such as hiding the mouse cursor and opening applications, but it can also be used for more serious attacks including retrieving all your personal [...]

Mitigating Smurf DoS Attacks

Tuesday, August 18th, 2009

Before looking at how to mitigate a Smurf attack, let’s first understand what it is and why it’s such a problem.   A Smurf works on a weakness of IP and ICMP by sending an ICMP packet to the broadcast address of a network. For example, I could send an ICMP (Ping packet) to every [...]

IP Address Spoofing Mitigation with Access Control Lists (ACL)

Monday, August 17th, 2009

IP spoofing is the act of camouflaging your IP address to make it look like you are someone else. Although IP spoofing is not an attack by itself, it is the starting point of many of the most common attacks found on today’s networks.   Most, but not all, of the spoofing attacks that take [...]