Continuing this series promoting the SANS SEC503: Intrusion Detection in Depth. In this post, we are looking at TShark statistics menu.
To see the statistics available, we leverage tshark -z help: Below shows a snapshot of this output.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -z help tshark: The available statistics for the "-z" option are: ... conv,eth conv,fc conv,fddi conv,ip conv,ipv6 conv,ipx conv,jxta conv,mptcp conv,ncp conv,rsvp conv,sctp conv,sll conv,tcp conv,tr conv,udp ...
When analyzing a PCAP, it is highly likely, you will look at the Protocol Hierarchy, let's do that.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r hydra_port_445.pcap -q -z io,phs =================================================================== Protocol Hierarchy Statistics Filter: sll frames:11337 bytes:1289873 ip frames:11337 bytes:1289873 tcp frames:11337 bytes:1289873 nbss frames:3925 bytes:767089 smb frames:3925 bytes:767089 vssmonitoring frames:14 bytes:868 ===================================================================
Looking at endpoints in a PCAP file, always helps to give visibility into the hosts seen on your network and how they were communicating, as it relates to bytes and packets.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r hydra_port_445.pcap -q -z endpoints,ip ================================================================================ IPv4 Endpoints Filter:<No Filter> | Packets | | Bytes | | Tx Packets | | Tx Bytes | | Rx Packets | | Rx Bytes | 10.0.0.102 11337 1289873 6866 812766 4471 477107 10.0.0.104 4491 514851 1755 191201 2736 323650 10.0.0.106 4445 510943 1709 187293 2736 323650 10.0.0.105 2246 246142 938 91528 1308 154614 10.0.0.90 150 17425 67 6955 83 10470 10.0.0.103 5 512 2 130 3 382 ================================================================================
Similarly, we can look at the TCP Endpoints.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r hydra_port_445.pcap -q -z endpoints,tcp | more ================================================================================ TCP Endpoints Filter:<No Filter> | Port || Packets | | Bytes | | Tx Packets | | Tx Bytes | | Rx Packets | | Rx Bytes | 10.0.0.104 445 4491 514851 1755 191201 2736 323650 10.0.0.106 445 4445 510943 1709 187293 2736 323650 10.0.0.105 445 2246 246142 938 91528 1308 154614 10.0.0.90 445 150 17425 67 6955 83 10470 10.0.0.102 57662 13 1420 7 828 6 592 10.0.0.102 52916 13 1400 7 844 6 556 10.0.0.102 52936 13 1400 7 844 6 556 ...
TCP (and similarly UDP) endpoints is helpful. As you see above, you also have the bytes and packets exchanged on the port the host was using at a particular point in time. For example, you see three different ports being reported for the endpoint at IP 10.0.0.102.
While endpoint information is helpful, you may instead wish to see conversations occurring between endpoints. Looking at Ethernet conversations is helpful to see hosts communicating on the local LAN. Maybe helpful to identify lateral movement. Most days, your internals hosts will be communicating with servers local to its' subnet or its router (default gateway). When there are many Ethernet addresses communicating which are not server or default gateway related, this may be a cause of concern.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -z conv,eth ================================================================================ Ethernet Conversations Filter:<No Filter> | <- | | -> | | Total | Relative | Duration | | Frames Bytes | | Frames Bytes | | Frames Bytes | Start | | 00:22:19:01:ef:0d <-> cc:b0:da:ba:42:39 39 2,532bytes 78 112kB 117 114kB 0.000000000 27.1526 ================================================================================
Above shows good insights into two MAC addresses communicating on the LAN.
Moving to IP conversations.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -z conv,ip ================================================================================ IPv4 Conversations Filter:<No Filter> | <- | | -> | | Total | Relative | Duration | | Frames Bytes | | Frames Bytes | | Frames Bytes | Start | | 146.66.65.213 <-> 192.168.0.26 37 2,424bytes 76 112kB 113 114kB 26.904525000 0.2481 72.21.91.29 <-> 192.168.0.26 2 108bytes 2 120bytes 4 228bytes 0.000000000 0.0019 ================================================================================
We now have better insights into the IP communication. As expected with the conversations we have information on the frames, bytes, duration, etc.
Digging a bit deeper ...
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -z conv,tcp ================================================================================ TCP Conversations Filter:<No Filter> | <- | | -> | | Total | Relative | Duration | | Frames Bytes | | Frames Bytes | | Frames Bytes | Start | | 192.168.0.26:50237 <-> 146.66.65.213:80 76 112kB 37 2,424bytes 113 114kB 26.904525000 0.2481 192.168.0.26:50230 <-> 72.21.91.29:80 2 120bytes 2 108bytes 4 228bytes 0.000000000 0.0019 ================================================================================
Now we have a more intimate view of the communications. We are able to see fully the session as it relates to the IP addresses and ports the communications occurred on. More importantly, you can see the frames, bytes, duration, etc.
Now that we know there is HTTP communication occurring above, let's grab some HTTP statistics.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -z http,stat =================================================================== HTTP Statistics * HTTP Status Codes in reply packets HTTP 200 OK * List of HTTP Request methods GET 1 ===================================================================
Above, we see information on the HTTP status code and the request method. Looks like only 1 request method was found in the PCAP.
This can further be confirmed by extracting the http.request.method field
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -T fields -e http.request.method | sort | uniq GET
Moving on with other HTTP statistics, looking at the request tree
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -z http_req,tree ================================================================================================================================================================= HTTP/Requests: Topic / Item Count Average Min Val Max Val Rate (ms) Percent Burst Rate Burst Start ----------------------------------------------------------------------------------------------------------------------------------------------------------------- HTTP Requests by HTTP Host 1 0.0041 100% 0.0100 26.912 worldtoptop.com 1 0.0041 100.00% 0.0100 26.912 /wp-content/uploads/2011/05/kaieteur_falls.jpg 1 0.0041 100.00% 0.0100 26.912 -----------------------------------------------------------------------------------------------------------------------------------------------------------------
Above we see a request was made to worldtop.com for a file kaieteur_falls.jpg. Looking to the server tree ...
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q -z http_srv,tree ================================================================================================================================================= HTTP/Load Distribution: Topic / Item Count Average Min Val Max Val Rate (ms) Percent Burst Rate Burst Start ------------------------------------------------------------------------------------------------------------------------------------------------- HTTP Requests by Server 1 0.0041 100% 0.0100 26.912 HTTP Requests by Server Address 1 0.0041 100.00% 0.0100 26.912 146.66.65.213 1 0.0041 100.00% 0.0100 26.912 worldtoptop.com 1 0.0041 100.00% 0.0100 26.912 HTTP Requests by HTTP Host 1 0.0041 100.00% 0.0100 26.912 worldtoptop.com 1 0.0041 100.00% 0.0100 26.912 146.66.65.213 1 0.0041 100.00% 0.0100 26.912 HTTP Responses by Server Address 1 0.0041 100% 0.0100 27.153 146.66.65.213 1 0.0041 100.00% 0.0100 27.153 OK 1 0.0041 100.00% 0.0100 27.153 -------------------------------------------------------------------------------------------------------------------------------------------------
Above shows request by server address, hostname and then ultimately the server response. So we are confident that the request made to this server was returned successfully.
To extract the file "kaieteur_falls.jpg" file, we do the following:
1. ┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r securitynik_kaieteur_falls.pcap -q --export-objects http,/tmp/ 2. ┌──(rootđź’€securitynik)-[~/tshark-series] └─# ls -al /tmp/kaieteur_falls.jpg -rw-r--r-- 1 root root 107720 Aug 18 22:52 /tmp/kaieteur_falls.jpg 3. ┌──(rootđź’€securitynik)-[~/tshark-series] └─# xdg-open /tmp/kaieteur_falls.jpg &
At 1 above, we exported content from HTTP. In 2 we performed ls on the file to verify its existence. Finally in 3, we opened the file using xdg-open. This is what the file looks like.
The above image is that of the Kaieteur Falls in Guyana South America. It is considered to be the largest single drop water falls in the world. Go for a visit when you get a chance if you are a nature lover.
Now that we've look at HTTP, let's transition look at io,stat. Specifically, let's look at traffic from the perspective of two minutes intervals.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r MS17_010\ -\ exploit.pcap -q -z io,stat,120 ================================== | IO Statistics | | | | Duration: 1359.431051 secs | | Interval: 120 secs | | | | Col 1: Frames and bytes | |--------------------------------| | |1 | | Interval | Frames | Bytes | |--------------------------------| | 0 <> 120 | 1074 | 845196 | | 120 <> 240 | 6 | 912 | | 240 <> 360 | 11 | 2058 | | 360 <> 480 | 11 | 2042 | | 480 <> 600 | 27 | 10644 | | 600 <> 720 | 13 | 2524 | | 720 <> 840 | 6 | 912 | | 840 <> 960 | 6 | 912 | | 960 <> 1080 | 11 | 1930 | | 1080 <> 1200 | 15 | 2686 | | 1200 <> 1320 | 6 | 912 | | 1320 <> Dur | 123 | 95666 | ==================================
As we look above, we see a pattern of 6 frames and 912 bytes at 4 different two minute intervals.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r MS17_010\ -\ exploit.pcap -q -z io,stat,120,"MAX(frame.time_relative)frame.time_relative",ip.addr==10.0.0.90,"MIN(frame.time_relative)frame.time_relative" -t ad ===================================================================== | IO Statistics | | | | Duration: 1359.431051 secs | | Interval: 120 secs | | | | Col 1: MAX(frame.time_relative)frame.time_relative | | 2: ip.addr==10.0.0.90 | | 3: MIN(frame.time_relative)frame.time_relative | |-------------------------------------------------------------------| | |1 |2 |3 | | Date and time | MAX | Frames | Bytes | MIN | |-------------------------------------------------------------------| | 2018-02-24 22:20:15 | 85.649770 | 1074 | 845196 | 0.000000 | | 2018-02-24 22:22:15 | 206.367818 | 6 | 912 | 145.984684 | | 2018-02-24 22:24:15 | 327.462658 | 11 | 2058 | 266.594469 | | 2018-02-24 22:26:15 | 467.993210 | 11 | 2042 | 387.750787 | | 2018-02-24 22:28:15 | 596.869106 | 27 | 10644 | 528.390247 | | 2018-02-24 22:30:15 | 699.492896 | 13 | 2524 | 618.804501 | | 2018-02-24 22:32:15 | 820.258716 | 6 | 912 | 759.858036 | | 2018-02-24 22:34:15 | 941.086732 | 6 | 912 | 880.615586 | | 2018-02-24 22:36:15 | 1070.588021 | 11 | 1930 | 1001.436265 | | 2018-02-24 22:38:15 | 1187.508831 | 15 | 2686 | 1130.896538 | | 2018-02-24 22:40:15 | 1308.274574 | 6 | 912 | 1247.825192 | | 2018-02-24 22:42:15 | 1359.431051 | 123 | 95666 | 1351.488699 | =====================================================================
Above we expand the io,stat grabbing additional information of a particular IP.
Finally, if you wanted to gain insights into the SMB commands seen in the PCAP, you can use smb,srt.
┌──(rootđź’€securitynik)-[~/tshark-series] └─# tshark -n -r MS17_010\ -\ exploit.pcap -q -z smb,srt =================================================================== SMB SRT Statistics: Filter: smb.cmd Index Commands Calls Min SRT Max SRT Avg SRT Sum SRT 43 Echo 2 0.000072 0.000087 0.000080 0.000159 50 Trans2 2 10.136100 10.242747 10.189424 20.378847 115 Session Setup AndX 4 0.000081 0.000117 0.000099 0.000396 117 Tree Connect AndX 2 0.000103 0.000110 0.000107 0.000213 Filter: smb.trans2.cmd Index Transaction2 Commands Calls Min SRT Max SRT Avg SRT Sum SRT Filter: smb.nt.function Index NT Transaction Sub-Commands Calls Min SRT Max SRT Avg SRT Sum SRT 0 <unknown> 2 0.000087 0.000154 0.000121 0.000241 ==================================================================
Ok! That's it for this post. There are many more statistics for you to take advantage of, depending on the protocols you are using. Have fun exploring!
References:
tshark - The Wireshark Network Analyzer 3.4.7
All PCAPs can be found at my GitHub page
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