I am utterly sorry for posting links of the pdf's because of the absence of formatting tools here. Links are perfectly safe as they are directly opened on the Google Storage interface in the browser. You may also wish to save them on your local machines.
1) To understand how and why VOIP calls work, you must first
understand what a codec is and what role does it play in VOIP. Although, this may not be necessary to understand VOIP capture but it gives you insight on the working of VOIP.
As
you can see, a CODEC samples audio coming into your audio device and
using an algorithm converts into a digital output which can be used up
in making audio files(.mp3, .m4a), understandable by the computer.
The same mechanism is followed vice versa while displaying some sound through your headphones or speakers.
2) So, VOIP consists of an RTP protocol which is responsible for carrying the audio stream. The RTP header consists of the appropriate CODEC used by the VOIP calling software but Wireshark uses its default set to analyse the stream without us specifying the CODEC. The RTP protocol is built on the UDP protocol.
3) In the following video, I have explained how to use Wireshark to capture the Audio Stream.
A Java applet is a small application
which is written in Java and delivered to users in the form of bytecode.
The user launches the Java applet from a web page, and the applet is then
executed within a Java Virtual Machine (JVM) in a process separate
from the web browser
itself. A Java applet can appear in a frame of the web page, a new application
window, Sun's AppletViewer,
or a stand-alone tool for testing applets.
The Applets are used to provide interactive features to web
applications that cannot be provided by HTML alone.They can
capture mouse input
and also have controls like buttons or check boxes.
An untrusted
applet has no access to the local machine and can only access the server it
came from. This makes such an applet much safer to run than a standalone
executable that it could replace. However, a signed applet can have full access
to the machine it is running on if the user agrees.
This attack will create a malicious Java applet hosted on the
attacker's machine within a local copy of a famous website (Gmail, Facebook,
...) and start a listener. Once the victim will connect to us, he/she will bind
to us and a session will be created on the attacker's machine.
A
bastion host is a computer that is fully exposed to attack. The system is on
the public side of the DMZ,
unprotected by a firewall or filtering router. Frequently the roles of these
systems are critical to the network security system.
