Category Archives: analysis

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:

use tshark & grep offset 0010

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

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

Shell hiding in image files

One day, we noticed strange GET request towards our JBoss server:

From the request above, you’ll quickly noticed that this attack leveraging Apache Struts vulnerability from CVE-2017-5638.

The request tried to execute command below:

“-O” : writes the documents to file.
“-” : if is used as file, documents will be printed to standard output, disabling link conversion.
“-q” : quiet (no output)

As you see, it tried to fetch image (jpeg file) from Seems normal right?
We fetch the file & take a look at the jpg file:

ASCII?? Not JPEG?? hmm..
Here’s whats inside the “logo.jpg” file:

We noticed there are several other file fetched; possibly a config file & bin file.
Let’s fetch those file!

Here is the config file:

Not sure it is. Maybe bin file to run a process:

Lets see if the file is packed:

Yup. So lets unpacked the file using UPX:

Overall, looks like the attacker want to hack our servers & turn it into his own crypto currency mining machine.
Typical behavior of attack we see in this time where the crypto currency is rising. People hack to make profit. 🙂

Here the MD5 for file above:

Dionaea simple analysis

Dionaea exploit analysis

We’ll using python bundled with Dionaea:

It will open a python console. Enter the code below line by line:

It will produce test.bin file in /tmp/ folder.

Now we analyze it and dump the output to another file:

You should see something like this:

As you can see, the malicious URL is hxxp://