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How secure is your network?

David Dodd

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Top Stories by David Dodd

Having your network environment protected with the latest virus protection, control what software is installed and allowed to run, restrict ingress and egress network access, protect web browsing, limit user account access, update security patches, change management practices, etc. All these efforts are critical to follow in the corporate environment but all will fall short if you don't have the proper monitoring in place to detect badness on your network and to respond quickly and effectively when it happens. When your network has the proper monitoring in place and knowledgeable engineers to monitor for outbreaks you will begin to have better visibility of how network traffic flows in your environment. When you understand how traffic flows on your network you can respond better when badness happens. I will demonstrate how to use a number of tools to analyze a memory... (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)

Tutorial: OpenSSL Command

The OpenSSL is based on SSLeay library developed by Eric A. Young and Tim J. Hudson and licensed under an Apache-style license. OpenSSL has lots of features but I will cover encoding, checksums, encryption, passwords and pass phrases. Many Linux distributions have OpenSSL as part of the bundled packages and is most likely located in /usr/bin. To find it on your system type: $ which openssl /usr/bin/openssl $ openssl version OpenSSL 1.0.0a 1 Jun 2010 Versions may vary and currently openssl-1.0.0d Feb 8 is the current version. Most of the examples that are found in this document sh... (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)

Network Security: Arp Cache Poisoning and Sniffing Packets

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 mar... (more)