Sep 4, 2012

Command Your Windows

Is command line obsolete in Windows system? What can you do if have no GUI? How useful are Windows command to a hacker or pen-tester when they obtain a remote shell to a windows machine?

I have wrote an article titled "Command your Windows", which is published in this month PenTest magazine (September). In this article, I will be sharing on some of the useful windows commands that a hacker or pen-tester can use when obtaining a remote shell to the system.

This magazine can be purchase on-line from PenTest Magazine website.

Please post your comments regarding this article here.
You can also email me if you are interested in this article.

Aug 3, 2012

Article in PenTest Magazine

My article on how to hack using Teensy was published in this month (July) issue of PenTest (Web App) Magazine . It is titled "Pentesting with Teensy", which talks about how you can emulate the device as a HID (Human Interface Device) and inject attack codes and execute commands in the system.

This magazine can be purchase on-line from PenTest Magazine website.

Please post your comments regarding this article here.
You can also email me if you are interested in this article.

May 31, 2012

WhatsApp InSecurity

I have recently wrote an article titled "WhatsApp InSecurity", which should be published on June issue of Hakin9 magazine. But due to some logistic issues, it is finally published on the July August issue. This article talks about how you can extract the message and photo that were send via WhatsApp.

This magazine can be purchase on-line from Hakin9 Magazine website.

Please post your comments regarding this article here.
You can also email me if you are interested in this article.

There is a video on the related demonstration, which I previously posted in "Can you extract message and photo from WhatsApp"

Mar 12, 2011

Suspicious PDF

Have not been doing malware analysis for awhile. I have receive a suspicious PDF file and decided to do some analysis using REMnux.

Analysis Report:

File: china.pdf
Size: 131336

First, by using the, notice some javascript were embedded in the PDF file.

With, it can extract the embedded codes in the file. It also confirm that the PDF file contains javascript.

By analysing the output, it shows obfuscated javascript. Possible Heap Spray attack.

Jsunpack-n shows that suspicious shellcodes were embedded. But no known exploit found.

Aug 14, 2010

XSS found in website was found to be vulnerable to Cross Site Scripting(XSS) vulnerability, which could be exploited using malicious scripts.

Vulnerability Description:
================== is a famous advertising network site that brings web users, websites and marketers together. The XSS vulnerability is found in the Default.aspx page. Script can be injected to the Message and Returnurl parameters. This can be exploited by injecting arbitrary HTML and malicious script code, which will execute in a user's browser session. Unvalidated redirection and forwarding is also possible.

Vulnerability testing:
Vulnerable URL:
Tested with: Firefox 3.5 and Internet Explorer 7 on Windows XP SP3

A simple "alert("You are hACked by w01f")" script was injected to the "Default" page. It was executed and display on the web browser. Malicious script could be executed using this method.

Exploit Code using "alert": Download

- Update on 19 Aug

Below is the video demonstration on exploiting the XSS vulnerability using redirection. It will redirect to my blog. Hacker can redirect to a spoofed Linkbucks site with malicious code.

Exploit Code using redirection: Download

The Message and ReturnURL parameters need to be properly sanitized after a user's logging out. The Linksbuck support team was contacted on the vulnerability. The support ticket is "#KHT-97974-227" but so far no fixed was done.

Jun 30, 2010

Reverse Engineering Flash games

Majority of online games uses Adobe Flash these days. While trying out this online games, i was surprised find out that there are still many unsecured flash games. Some are still sending the score in clear text (shown below). I think it is the basic for all online games to protect the score (or data) while submitting back to the server. I even created a simple Web challenge (Data Manipulation attacks for Web applications) on this flaw several months back, to teach and share this knowleadge.

Hashing, good enough?
But there are others that try to protect the score that is transmit back to the server using hashing. They hash the score with a secret key or "Salt". It look safe to many by protecting the data transmission. But they did not protect the Flash itself. It can be easily decompiled to extract the key (shown below) or change the code. Flash code should be obfuscated so that decompiling could not be easily done.

Below is the example of the unsecured Flash game that i came across recently. I had inform their administrator about the possible hacking on their game but they never reply to find out more. So i decided to share some of my finding and show how easy it can be reverse engineered.

Below is function that calls the hashing and submit the user's info and score.

Below shows the "key" or "Salt" that is use for the hashing.

-Update on 19 Jul

After the programmer of the game (that i previously mentioned) tried to secure their code, they were hacked again. This time it looks like an Indonesian hacker, which uses the name "Rank 1 to 10 all cheated" in Bahasa Indonesia, put himself on the top of the score table (with obvious reason).

Looks like the programmer don't understand malay language at all as the name was listed for a few days and was not removed. Time for me to send them a note again.

Jun 8, 2010

DOS vulnerability on Internet Browser

While contributing to the OSVDB. I notice about the recent DoS (Denial of Service) vulnerability on the Internet Browser and decided to research on it.

Internet Browser such as IE and Firefox contains a flaw that may allow a remote denial of service. The vulnerability can be triggered when processing a web page with a large number of various invalid request such as NNTP, NEWS and Mailto. This may cause the system to crash due to high resources consumption.

I have tested on some of these exploits. Test at your own risk.

Affected Browser: Internet Explorer, FireFox, Chrome, Opera, etc
OSVDB: 65110
Exploit Code: Download