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Open Source, Future Technology, and the Web

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Wireshark recipe to capture packets from the command line

August 29th, 2007 · No Comments · howto, information security, wireshark

Wireshark is a great utility for doing packet capture and analysis. It is an open source suite of applications that evolved from the ethereal project. My friend Angela Orebaugh has written comprehensive books on both Wireshark and Ethereal (I recommend them both!).

Sometimes while troubleshooting, it is necessary to run packet captures as part of an automated process. For example, you want to debug the network behavior of an application that runs at 1:15am. It would be really handy to have a way to run wireshark from a shell script or batch file. Enter tshark!

Tshark (text {wire}shark) is a command line version of wireshark. Here are a tshark few recipes I’ve used in the past:

tshark -i 4 (capture packets from interface #4 and print headers to STDOUT)

tshark -i4 -w output.cap (capture packets to the file output.cap)

tshark -i 4 -b files:10 -b filesize:9999 -w output.cap (capture packets in a ringbuffer of 10 files, each up to 9.9 MBytes)

Free the packets! :)

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web2.0 conference: twitter, jaiku, dodgeball

April 22nd, 2007 · 3 Comments · information security

Social networks have been exploding during the past two years.  I think 2007 will be the year that social networking went mainstream.Here are a few topics worth exploring if you are a geek:

Social presence sites:

  • Twitter - answers the question “what are you doing right now?” and is accessible via web and SMS
  • Jaiku - Twitter plus a bunch more functionality (and an XML-RPC API)
  • Dodgeball - SMS messages when you are near your friends.

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Press Release: libSNA

December 10th, 2006 · No Comments · press releases, web 2.0

Abe Usher
Voice 703.879.5710
Fax 866.337.3778


In light of the explosion in social networking sites (myspace, facebook, xanga et cetera) and web 2.0 communities, social network analysis is hotter than ever.

A new open source library released today (libsna) helps social scientists and software developers rapidly create experiments and computer programs to understand emerging social networks.

Washington, DC, December 11, 2006
In light of the explosion in social networking web sites (MySpace, FaceBook, Xanga) the field of social network analysis (SNA) is hotter now than ever before. The sale of for over $500 million to News Corp underscores the value and importance of social networks. Marketing gurus want to understand how to tap into social networks to maximize sales. Law enforcement officials want to minimize the risks that social networks pose to teens and children. Young adults in Generation Y want to get plugged into these networks. Does anyone really understand social networks?

“I created libSNA out of necessity” says Washington, DC, based Abe Usher, a well-known information security expert and the developer of libSNA. “During my graduate studies in 2003, I experimented with a number of leading SNA tools. Unfortunately, none of the software I found this was scalable or robust enough to analyze very large (50,000+ person) networks. I became re-interested in social networks in early 2006 but found that there was still a lack of useful tools. I created libSNA as a tool to help social scientists and computer programmers effectively analyze the networks emerging from Web 2.0.”

“On-line social networks are facilitating relationships between geographically distributed persons through ‘virtual communities’ at a staggering rate. The emergence of large-scale virtual communities on MySpace, SecondLife, Flickr and similar sites continues to have an increasingly important influence on life beyond the Internet. With hundreds of millions of participants, on-line social networks are no longer just kid stuff.”

libSNA is available on-line through the web site

For more information, please contact Mr. Usher directly at +1.703.879.5710

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Hacking a U3 USB drive

June 15th, 2006 · No Comments · USB, information security

Robert McGrew wrote an article describing how he hacked the auto-run feature on a U3 USB thumbdrive:

hack u3 thumbdrive description

The implications of this are simultaneously interesting and disheartening. Interesting because computer hobbyists could use the capability of hacking an autorun USB device to create some very novel applications. Disheartening because this may lead to yet another attack vector for malicious hackers. Time will tell what the implications will be!


Consider the positive uses of this technology:

Users can make custom U3 applications that “autorun”:

  • Anti-virus software from USB
  • Spyware removal from USB
  • System integrity checks on OS files (.dlls and .exes)
  • Users can replace the U3 launcher application with one of their choosing (e.g. Launchy)

Consider the negative implications of this technology:

  • Hackers write viruses/backdoors that autorun from USB drive
  • Users modify their U3 drive to subvert applications with DRM technology
  • Due to risks, organizations end up banning USB devices from use.

To have a better idea of what this might mean, check out the list of portable applications on Wikipedia.*

What’s your opinion? Will this be good or bad?

* Applications that can run off of a USB drive.

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