How secure is your network?

David Dodd

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In a switched network environment packets are sent to their destination port by MAC address. This requires that hardware be able to create and maintain a table associating MAC addresses to ports. In a switched environment packets are only sent to devices that they are meant for. Even in this switched environment there are ways to sniff other devices' packets. One such way is to spoof your MAC address and poison the arp table. Since there is no state information about ARP traffic kept, as it's a simple protocol, the arp cache can be overwritten (unless the entry was explicitly marked as permanent). Arp cache poisoning puts the attacker in position to intercept communications between the two computers. Computer A believes it is communicating with Computer B, but because of the poisoned arp table, the communication actually goes to the attacker's computer. The attacker ... (more)

Performing a Penetration Test on a Customer’s Network

When performing a penetration test on a customer’s network by simulating an attack and trying to find a way inside many forget there is an easier way. Many networks have well established security protection through firewalls, Intrusion Detections/ Protections Systems that will alert to your presents. Performing a vulnerability scan using tools such as NeXpose, Nessus, nmap, etc will alert many systems. By performing some research on the target and learn what the company does you can narrow your attack. By using some social engineering you can email your payload to an inspecting v... (more)

Capture File Filtering with Wireshark

Intrusion detection tools that use the libpcap C/ C++ library [1] for network traffic capture (such as Snort [2] and Tcpdump [1]) can output packet capture information to a file for later reference. The format of this capture file is known as pcap. By capturing packet data to a file, an investigator can return later to study the history of an intrusion attempt – or to turn up other important clues about clandestine activity on the network. Of course, the traffic history data stored in a pcap file is much too vast to study by just viewing the file manually. Security experts use spe... (more)

Metasploit Nessus Bridge on Ubuntu

Nessus is a vulnerability scanner program; it is free for personal use using the nessus for home. They also have a nessus for business which requires a fee. I will be discussing the nessus for home use and using it with the popular metasploit framework. Acquire the latest release of nessus homefeed Nessus-4.4.1-ubuntu1010_i386.deb and register for the activation code. Follow the instructions listed in the document ion for installing with Ubuntu and start to configure. Nessus daemon cant be started until nessus has been registered and the plugin download has occurred. $ sudo /opt... (more)

Planning, Scoping and Recon Techniques

The purpose of this article is to describe some tools and techniques in performing the planning, scoping, and recon portion of a penetration test. In covering these tools and techniques the reader will learn how to use them to find vulnerabilities in their organization and help improve security posture. Some other names for this first phase of penetration testing are; OSINT (Open Source Intelligence), Footprinting, Discovery, and Cyberstalking. Introduction During reconnaissance we'll gather information from public sources to learn about the target and try to find what is importan... (more)