*Corresponding author: [email protected]
Detecting Threats in Network Security by Analyzing Network Packets
using Wireshark
Abdulalem Ali *, Arafat Al-Dhaqm, Shukor Abd Razak Faculty of Computing, University Technology of Malaysia
Abstract
Nowadays it is very important to maintain a high level security to ensure safe and trusted communication of information between various organizations. Computer networks have kept up growing in size, complexity and, over-all, in the number of its users as well as being in a permanent evolu-tion. Hence, Packet sniffers are useful for analyzing network traffic over wired or wireless networks. In this paper, security network protocol analyzer, wireshark, has been used to capture the data from Center of Information and Communication Technology (CICT) network traffic in Universiti Teknologi Malaysia. These data can be applied as a sample to test it by wireshark. In-deed, the data packets have obtained are malware and non-malware. The aim of this paper is to analyze these data in order to help network administrator to monitor any abnormal behavior in the network and log it. The information gathered from CICT and the data analyzed using matching algorithm. The re-sults gave high implication in the analysis of network and increase significant essence in network security to detect any threats that violate system security.
Keywords: Matching Algorithm Network Security; Wireshark; .
1. Introduction
Packet Sniffing is a technique for monitoring every packet that crosses the network. A packet sniffer is the best open source software available that monitors network traffic. The security threat presented by sniffers is their ability to capture all incom-ing and outgoincom-ing traffic, includincom-ing clear text passwords and usernames or other sen-sitive material. Sniffer is a program running in a network attached device that pas-sively receives all data link layer frames passing through the device's network adapt-er. It is also known as network or protocol analyzer or Ethernet Sniffadapt-er. The packet sniffer captures the data that is addressed to other machines, saving it for later analy-sis. It can be used legitimately by a network or system administrator to monitor and troubleshoot network traffic either in local area network or in host system [1]. In this paper, security network protocol analyzer wireshark has been used to capture the da-ta from CICT network traffic. These dada-ta can be applied as a sample to test it by wireshark. Indeed, the data packets have obtained are malware and non-malware.
IRICT 2014 Proceeding
The aim of this study is to analyze these data in order to help network administrator to monitor any abnormal behavior in the network and log it. The information gath-ered from CICT and the data were analyzed using open source tools. The rest of this paper is structured as follows. Section 2 presents tools for traffic analysis. Priciple of network sniffer in section 3. In Section 4, implementation of network sniffer. Meth-odology in section 5. In Section 6, The results. Finally, the conclusion is presented in Section 7.
2. Tools For Traffic Analysis
Wireshark
Previously known as Ethereal, Wireshark, as it is currently known, is a packet ana-lyzer employed in analyzing troubleshooting of networks. The change of name was done in May, 2006 because of a trademark issue. Wireshark captures packets by means of PCAP. It is a cross-platform which is capable of running in various types of operating system that are Unix-like as well as Windows and Solaris. In Wireshark, it is not only the traffic meant for an address constructed for the particu-lar interface that can be seen, but rather everyone is visible there [2]. This is possible because the user can make use of an interface allowing a loose mode.
Figure.1: Wireshark tool.
Wireshark makes it possible for the user to capture packets moving across the whole network on a given interface per time. The capture tool is one of the basic tools. The user is able to carry out the packet, and capture using the capturing menu which has a number of options to choose from based on the analysis desire. It is also possible for the analyst to set filters such that unwanted traffic that can be avoided during the capture [3]. Wireshark however, has a limitation in that it does not pos-sess intrusion detection capability.
The user gets no warning when an intruder tampers with something on the network and wireshark does not exercise control over the network. Space consumption is quite much with its 18MB file installation taking up to 81MB and 449MB respec-tively in Windows and Linux [4]. However, the Wireshark GUI is quite user friend-ly.
Soft Perfect Network Protocol Analyzer (SPNPA)
This is an advanced, professional analyzer. It analyzes data passing through the di-al-up connection or the Ethernet card and presents it in comprehensible form. It is a practical tool for different network personnel or any user requiring a broad picture of personal network traffic. SPNPA results are very easy to understand and also allows for defrayments of network packets and reassembling into streams.
CAPSA
This is an indispensable tool for network administrators. It is a freeware, designed for personal use or small business and useful for network monitoring, diagnosis and troubleshooting. Packet capturing is real-time, forensics is reliable, monitoring is on 24/7 basis, protocol analysis is advanced and packet decoding is in-depth.
3. Principle of Network Sniffer
Network sniffer uses the local media; the transforming data can be detected by any computer system. Data frame is received by each computer’s Ethernet network adapter, generating either a data frame that is a match of its own hardware address or a broadcast frame. With the two data frame type, for Ethernet network adapter, the data are transformed into upper processing, whereas it discards the other types of frames. In promiscuous mode, the adapter can accept data transmission in every segment and transfer same to the OS for further treatment. Data transformed within the sharing network can be detected in network sniffer as shown in Figure 2[5].
Figure.2: Implementation of Network Sniffer
4. Implementation Of Network Sniffer
For the completion of network data collection, setting of network detector are done in the physical segment and linked to export routers on the network. This way, de-tection of all packets in the network is possible. NICO and NICI are the two adapters with which the network detector is configured as a host. While the former serves as the communication interface, the latter is set as the promiscuous mode and linked to the router at the same hub shown Figure 3.
Figure.3: Model of the Network Sniffing.
Packer Sniffer
A packet sniffer ‘sniffs’ information passing through a system, and stores/presents the content of the fields in this message. It is the tool for monitoring communication between protocol entities. It is a passive tool; only observing communication without being responsible for initiating it; packets received are also not directly addressed to it, it only receives copies The typical packet sniffer set-up is shown in Figure 4 The protocols (IP) and applications are on the right. The sniffer is represented by the rec-tangular broken line. It is a mere addition to the regular computer software. It is made up of the packet capture library and the packet analyzer. The packet capture li-brary receives a copy of information (link-layer frame) transmitted over the comput-er; encapsulation of information through higher layer protocols, e.g. DNS, HTTP, etc is done in link layer frames transmitted through physical media.
.
Figure 4. Packet Sniffer Structure
The packet analyzer is the other component of the sniffer. It is responsible for dis-playing the contents of all fields in a protocol communication. To be able to do this, it must have an understanding of the structure of protocol communication. For ex-ample, if we intend to display the component fields of the communication on the HTTP protocol. The packet analyzer can identify the IP datagram format by com-prehending the Ethernet frame format. It is also able to extract the TCP within the datagram. It is also able to comprehend HTTP protocol and will be able to identify the content of the first bytes of an HTTP message
5. Methodology
Data of computer send through the network in the form of packets. These packets are the group of data is actually directed to the certain designated system. In reality, most of data sent through the network which need to predefine it before send it to the destination and all the data are going directly to a particular computer.
There are many examples of packet sniffing software available on the internet for free that can be run on different platforms including windows and Linux. In our ex-periment, wireshark network analyzer is the one that will use to sniff network traffic in CICT department. These data traffic will be examined and compared with one pattern or signature form in order to find any abnormal pattern in these data. Actual-ly, two kinds of data have been getting, one malware and the other one non-malware. So we are going to test these data using one software tool to analyze it.
A. Sniffing Process
Here we are going to talk in a brief about sniffing process and our analysis imple-mented by wireshark software. The following steps describe sniffing process base on [6]:
Packet sniffer collects raw binary data from the wire. Typically, this is done by switching the selected network interface into promiscuous mode
Captured binary data is converted into a readable form.
Analysis of the captured and converted data. The packet sniffer takes the captured network data, verifies its protocol based on the information extracted, and begins its analysis of these protocols for specific features.
6. Results
The data packets were obtained from CICT department. These data packets were al-ready captured from the network by wireshark. The data can be classified into two type malware and non-malware. When the data packet was compared with signature used one software tool implemented via matching algorithm to give us analysis pa-rameters. This software can be used to compare the payload data for the selected protocol with a particular pattern as shown in the Figure 5. In our experiment, we used TCP payload string and compared with the small size of the pattern. In each time we compared around five packets with a specific pattern or signature in one tri-al.
In the above Figure 5, there are two input places, the first one is a load pattern input where you can type the specific signature pattern inside and in the second place for input is load string, this place can insert one or more packets to compare with pat-tern.
After we insert the two inputs together, we press quick search algorithm button to get the following parameters from the software.
First Testing using Malware Data Packets:
We have two types of data packets which obtained from CICT organization, so that our experiment will be implemented in two stages. The first test is dealing with malware packet. Table 1 shows malware packages comparisons.
Table 1. Number of Comparison Packets using Matching Algorithm
I n f a
In the above table, the data packets were tested three times, in the first comparison, we used five packets for TCP protocol to compare with signature (specific pattern). We observed that the number of comparisons is 537 and the time consuming is 0.047. In the second comparison, we used six data packets so that we observed that the number of comparisons is increased but the time still stable. In the third compari-son, we decrease the data packet into four therefore we found the number of compar-isons decreased also and the time for total search was decreased.
Figure.6: Malware Testing Payload using Matching Algorithm
We have observed that, from Figure 6, the graph starting point always from the to-tal search time. The first line, the red line, indicates that the maximum number of comparisons reaches more than 1000 and the second line is the blue line reaches less
537 0.047 608 0.034 606 0.047 343 0.0411 236 0.031 265 0.011 0 500 1000 1500 No. Comparison Total Search Time No. Comparison Total Search Time
Malware Testing Packet
Series3 Series2 Series1 No.
Com-parison Total Search Time No. Comparison Total Search Time
537 0.047 608 0.034
606 0.047 343 0.0411
than 600. The minimum number of comparisons was represented by the green line which indicates the lowest number, 236.the
Second Testing using Non-Malware Data Packets:
The second test in our experiments was non malware data packets in order to com-pare with specific pattern. Table 2 shows the non-malware packages comparisons using match algorithm.
Table 2. Non-Malware packages Comparisons using Match Algorithm
In the first comparison, we used five data packets, then in the second comparison we used six packets in one times, and in the third comparison we used four packets in order to compare with specific pattern.
Figure 7. Non-Malware Packages Testing using Matching Algorithm
Figure 7 shows three lines, the green line indicates the maximum number of com-parisons and consuming time was about 0.0453. Then, it was followed by the red line that represented the second highest number after green line and consumed time for total search around 0.0391. The third line was the blue line that indicated the lowest number of comparisons and lowest time consumed. We observed that the highest point was 1160 and the lowest point was 343.
343 0.031 963 0.0359 780 0.047 1046 0.0391 870 0.063 1160 0.0453 0 2000 4000
Non-Malware Testing
Packet
Series3 Series2 Series1 No. Compar-ison Total SearchTime No. Comparison Total Search Time
343 0.031 963 .0359
780 0.047 1046 0.0391
7. Conclusion
One of the significant methods in network security nowadays is to use the network traffic analyzer in order to reveal any abnormal behaviour in the data transfer over the network. Network analyzer tools can be used to monitor and troubleshoot the network. Network administrator do not only use these tools to fix any violation in network system but also to avoid network failure and detect security vulnerabilities. Network sniffer is one of the passive attacks that can sniff the traffic and analyze it. Unlike network sniffing, it is a sniffer detector tools that can discover any sniffing attack through the network and prevent it. Sniffing network traffic is an illegitimate process unless if it used for security purpose. Two types of data analysis have been tested for packets malware and no-malware. Comparisons between packets have been made that uses different techniques depending on what administrator wants. The results showed that while we used the small size of patterns to compare within a group of packets for more than five packets, it will give us more satisfied results and the make network analysis more efficient.
References
[1] Ansari, S., Rajeev S.G., Chandrasekhar H.S., "Packet Sniffing: A Brief Introduction", IEEE Potentials, Jan. 2003, Volume: 21 Issue: 5, pp: 17-19 (2003).
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[3] Dulal C., et al. . Ethereal vs. tcpdump: A comparative study on packet sniffing tools for educational purpose. Journal of Computing Sciences in Colleges archive, Volume 20(4), pp 169-176, (2005
[4] All about Wireshark [Online] Available http://www.wireshark.org/.
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