Click here to close now.




















Welcome!

Microservices Expo Authors: Roger Strukhoff, Pat Romanski, Elizabeth White, Joe Pruitt, Ian Khan

Related Topics: Cloud Security, Industrial IoT, Microservices Expo, Adobe Flex, Agile Computing

Cloud Security: Article

Capture File Filtering with Wireshark

Needle in a Haystack

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 specialized filtering tools to search through the file for pertinent information. One way to look for clues in a pcap file is to use the Wireshark protocol analysis tool [3] and its accompanying command-line utility tshark.

Wireshark is included by default on many Linux distros, and if not, it is available through the leading package repositories. You can also download Wireshark through the project website [4]. In this article, I describe how to use Wireshark and tshark to search a pcap file for information on network activity. I will assume you already have a pcap file ready for investigation. For more on how to capture a pcap file with Tcp-dump, see my article “Intruder Detection with Tcpdump,” which is available online at the ADMIN magazine website [5].

tshark at the Command Line
The tshark utility is a simple tool included with the Wireshark package that lets you filter the contents of a pcap file from the command line. To get a view of the most significant activity, I use the following command:

$ tshark ‑nr dumpfile1.gz ‑qz "io,phs" > details.txt

The ‑n switch disables network object name resolution, ‑r indicates that packet data is to be read from the input file, in this case dumpfile1.gz. The ‑z allows for statistics to display after it finishes reading the capture file, the ‑q flag specifies that only the statistics are printed, and the > redirection
sends the output to the file called details.txt. See Figure 1 for the output of this information. To view a list of help commands used with tshark, type:

$ tshark ‑h

And for a list of ‑z arguments type:

$ tshark ‑z help

Figure 1

Say you would like to know whether a particular IP address appeared in a packet dump and what port it was connecting on. The following command line checks the dump file for the IP address 98.139.126.21:

$ tshark ‑V ‑nr dumpfile.gz ip.src == 98.139.126.21 | grep "Source port" | awk {'print $3'} | sort ‑n | uniq 80

The resulting output on the line following the command shows that the packet dump file recorded IP address 98.139.126.21 having connections on port 80.

If you were given a packet dump file and asked to find possible IRC traffic on your network, how would you do it? First, you would need to know what port numbers were associated with IRC traffic, and that could be accomplished with Google or by issuing the following command:

$ grep irc /usr/share/nmap/nmap‑services | grep tcp

Figure 2 shows the results of the preceding command.

Figure 2

Now I can search the packet dump and look for evidence of IRC traffic using the following commands:

$ tshark ‑nr dumpfile1.gz 'ip.addr==172.16.134.191 and tcp.port >=  6667 and tcp.port <= 6670 and irc' |  awk {'print $3,$4,$5,$6'} | sort ‑n | uniq ‑c

Figure 1: tshark statistics output.
Figure 2: Locating IRC port numbers with grep.
Figure 3: IRC connections found in the packet dump.
Figure 4: The Wireshark startup window.

The breakdown of this command is shown in Table 1, and the output is in Figure 3.

Figure 3

In the GUI
The Wireshark GUI application is easier on the eyes, and it provides some options that aren’t available at the command line. You can start Wireshark from the Application menu or from the terminal.  To load a capture file, select Open in the startup window (Figure 4) or select File | Open from the menubar.  Once you have a packet capture file loaded, you can start searching packet dumps within the Wireshark interface.

Figure 4

The Filter box below the Wireshark toolbar lets you enter criteria for the search. For instance, to search for all the Canonical Name records within the capture file, type in the following filter: dns.resp.type == CNAME (see Figure 5).  After you enter a filter, remember to clear the filter text to see the full file before starting a new search.

Figure 5

Table 1: Parts of a tshark Command

Option Description
‘ip.addr==172.16.134.191         This is my network
and tcp.port >= 6667                   Start of the port range
and tcp.port <= 6670                   End of the port range
and irc’                                           Searches for IRC traffic only
awk {‘print $3,$4,$5,$6’}             Prints the third through sixth patterns from each matching line
sort ‑n                                            Sorts according to string numerical value
uniq ‑c                                            Only prints the number of matches that are unique

Digging deeper, if I want to know how long a client resolver cached the IP address associated with the name cookex.amp.gapx.yahoodns.net (Figure 6), I would enter the following filter:

dns.resp.name == "cookex.amp.gapx. yahoodns.net"

Figure 6

The filter ip.addr == 10.37.32.97 gives information on all communications that involve 10.37.32.97 in the packet dump. If needed, use && to isolate to a specific protocol. The filter ip.dst == 10.37.32.97 or ip.src == 10.37.32.97 looks for a source or destination IP address.

How could I find the password used over Telnet between two IP addresses? For example, if a user at 172.21.12.5 is using Telnet to access a device at 10. 37. 140.160, I can enter:

ip.dst == 10.37.140.160 && ip.src == 172.21.12.5 && telnet.data contains "Password"

The preceding command will list the connections that meet the search requirement, and you can right-click on the packet and click Follow TCP Stream to view the password. (See Figures 7 and 8.)

Figure 7

Figure 8

Note: A much easier way to get the password on the network, if you were sniffing the traffic instead of reading from a capture file, would be to use ettercap, as follows:

$ ettercap ‑Tzq //23

To discover whether someone was viewing a suspicious web page, I can perform a filter search to find out what picture the person at IP address 10.225.5.107 was viewing at Yahoo (216.115.97.236) with the following filter:

ip.dst == 10.225.5.107 && ip.src == 216.115.97.236 && (image‑jfif || image‑gif)

Figure 9

Figure 9 shows the results. If you then right-click on a line in the output and select Follow TCP Stream for the results shown in Figure 10.
The second line in the Follow TCP Stream output specifies that wynn‑ rovepolitico.jpg is the image this person was viewing on the site.

Figure 10

Conclusion
Wireshark can do more than just watch the wires in real time. If you save a snapshot of network activity in a capture file in the pcap format, you can use Wireshark to search through the file to look for clues about nefarious activity.

In this article, I described how to search for information in a capture file using Wireshark and the tshark command-line tool.

Info

[1] Tcpdump and Libpcap: http://www.tcpdump.org/
[2] Snort: http://www..snort.org
[3] Wireshark: http://www.wireshark.org/
[4] Wireshark Download: http://www.wireshark.org/download.html
[5] “Intruder Detection with Tcpdump” by David J. Dodd: http://www.admin‑magazine.com/Articles/Intruder‑Detection‑with‑tcpdump/

More Stories By David Dodd

David J. Dodd is currently in the United States and holds a current 'Top Secret' DoD Clearance and is available for consulting on various Information Assurance projects. A former U.S. Marine with Avionics background in Electronic Countermeasures Systems. David has given talks at the San Diego Regional Security Conference and SDISSA, is a member of InfraGard, and contributes to Secure our eCity http://securingourecity.org. He works for Xerox as Information Security Officer City of San Diego & pbnetworks Inc. http://pbnetworks.net a Service Disabled Veteran Owned Small Business (SDVOSB) located in San Diego, CA and can be contacted by emailing: dave at pbnetworks.net.

@MicroservicesExpo Stories
Digital Transformation is the ultimate goal of cloud computing and related initiatives. The phrase is certainly not a precise one, and as subject to hand-waving and distortion as any high-falutin' terminology in the world of information technology. Yet it is an excellent choice of words to describe what enterprise IT—and by extension, organizations in general—should be working to achieve. Digital Transformation means: handling all the data types being found and created in the organizat...
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
You often hear the two titles of "DevOps" and "Immutable Infrastructure" used independently. In his session at DevOps Summit, John Willis, Technical Evangelist for Docker, covered the union between the two topics and why this is important. He provided an overview of Immutable Infrastructure then showed how an Immutable Continuous Delivery pipeline can be applied as a best practice for "DevOps." He ended the session with some interesting case study examples.
The Software Defined Data Center (SDDC), which enables organizations to seamlessly run in a hybrid cloud model (public + private cloud), is here to stay. IDC estimates that the software-defined networking market will be valued at $3.7 billion by 2016. Security is a key component and benefit of the SDDC, and offers an opportunity to build security 'from the ground up' and weave it into the environment from day one. In his session at 16th Cloud Expo, Reuven Harrison, CTO and Co-Founder of Tufin,...
JavaScript is primarily a client-based dynamic scripting language most commonly used within web browsers as client-side scripts to interact with the user, browser, and communicate asynchronously to servers. If you have been part of any web-based development, odds are you have worked with JavaScript in one form or another. In this article, I'll focus on the aspects of JavaScript that are relevant within the Node.js environment.
Alibaba, the world’s largest ecommerce provider, has pumped over a $1 billion into its subsidiary, Aliya, a cloud services provider. This is perhaps one of the biggest moments in the global Cloud Wars that signals the entry of China into the main arena. Here is why this matters. The cloud industry worldwide is being propelled into fast growth by tremendous demand for cloud computing services. Cloud, which is highly scalable and offers low investment and high computational capabilities to end us...
One of the ways to increase scalability of services – and applications – is to go “stateless.” The reasons for this are many, but in general by eliminating the mapping between a single client and a single app or service instance you eliminate the need for resources to manage state in the app (overhead) and improve the distributability (I can make up words if I want) of requests across a pool of instances. The latter occurs because sessions don’t need to hang out and consume resources that could ...
Approved this February by the Internet Engineering Task Force (IETF), HTTP/2 is the first major update to HTTP since 1999, when HTTP/1.1 was standardized. Designed with performance in mind, one of the biggest goals of HTTP/2 implementation is to decrease latency while maintaining a high-level compatibility with HTTP/1.1. Though not all testing activities will be impacted by the new protocol, it's important for testers to be aware of any changes moving forward.
"We've just seen a huge influx of new partners coming into our ecosystem, and partners building unique offerings on top of our API set," explained Seth Bostock, Chief Executive Officer at IndependenceIT, in this SYS-CON.tv interview at 16th Cloud Expo, held June 9-11, 2015, at the Javits Center in New York City.
This week, I joined SOASTA as Senior Vice President of Performance Analytics. Given my background in cloud computing and distributed systems operations — you may have read my blogs on CNET or GigaOm — this may surprise you, but I want to explain why this is the perfect time to take on this opportunity with this team. In fact, that’s probably the best way to break this down. To explain why I’d leave the world of infrastructure and code for the world of data and analytics, let’s explore the timing...
Learn how to solve the problem of keeping files in sync between multiple Docker containers. In his session at 16th Cloud Expo, Aaron Brongersma, Senior Infrastructure Engineer at Modulus, discussed using rsync, GlusterFS, EBS and Bit Torrent Sync. He broke down the tools that are needed to help create a seamless user experience. In the end, can we have an environment where we can easily move Docker containers, servers, and volumes without impacting our applications? He shared his results so yo...
Auto-scaling environments, micro-service architectures and globally-distributed teams are just three common examples of why organizations today need automation and interoperability more than ever. But is interoperability something we simply start doing, or does it require a reexamination of our processes? And can we really improve our processes without first making interoperability a requirement for how we choose our tools?
Cloud Migration Management (CMM) refers to the best practices for planning and managing migration of IT systems from a legacy platform to a Cloud Provider through a combination professional services consulting and software tools. A Cloud migration project can be a relatively simple exercise, where applications are migrated ‘as is’, to gain benefits such as elastic capacity and utility pricing, but without making any changes to the application architecture, software development methods or busine...
The Internet of Things. Cloud. Big Data. Real-Time Analytics. To those who do not quite understand what these phrases mean (and let’s be honest, that’s likely to be a large portion of the world), words like “IoT” and “Big Data” are just buzzwords. The truth is, the Internet of Things encompasses much more than jargon and predictions of connected devices. According to Parker Trewin, Senior Director of Content and Communications of Aria Systems, “IoT is big news because it ups the ante: Reach out ...
At DevOps Summit NY there’s been a whole lot of talk about not just DevOps, but containers, IoT, and microservices. Sessions focused not just on the cultural shift needed to grow at scale with a DevOps approach, but also made sure to include the network ”plumbing” needed to ensure success as applications decompose into the microservice architectures enabling rapid growth and support for the Internet of (Every)Things.
Our guest on the podcast this week is Adrian Cockcroft, Technology Fellow at Battery Ventures. We discuss what makes Docker and Netflix highly successful, especially through their use of well-designed IT architecture and DevOps.
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Arch...
Public Cloud IaaS started its life in the developer and startup communities and has grown rapidly to a $20B+ industry, but it still pales in comparison to how much is spent worldwide on IT: $3.6 trillion. In fact, there are 8.6 million data centers worldwide, the reality is many small and medium sized business have server closets and colocation footprints filled with servers and storage gear. While on-premise environment virtualization may have peaked at 75%, the Public Cloud has lagged in adop...
MuleSoft has announced the findings of its 2015 Connectivity Benchmark Report on the adoption and business impact of APIs. The findings suggest traditional businesses are quickly evolving into "composable enterprises" built out of hundreds of connected software services, applications and devices. Most are embracing the Internet of Things (IoT) and microservices technologies like Docker. A majority are integrating wearables, like smart watches, and more than half plan to generate revenue with ...
Rapid innovation, changing business landscapes, and new IT demands force businesses to make changes quickly. The DevOps approach is a way to increase business agility through collaboration, communication, and integration across different teams in the IT organization. In his session at DevOps Summit, Chris Van Tuin, Chief Technologist for the Western US at Red Hat, will discuss: The acceleration of application delivery for the business with DevOps