tcp/ip is the communication protocol for the net.   tcp stands for transmission 
control protocol.  ip stands for internet protocol. when your application wants 
to communicate with someone elses program,    via TCP.   it first sends a re-
quest packet 2 communicate,  it must be sent to the exact address.  then the 
server sends an accept packet then after a (handshake)  by the applications. 
TCP will setup a   (full-duplex).   the full duplex will occupy the communication 
line.   until on one of the two computers the application is closed.   tcp comm-
unicates with all your applications, browser, and network programs.
 

tcp/ip has seven layers. they are.

Layer 1: Physical
sends/receives bits along a medium.

Layer 2: Data Link
Performs the actual sending. Detects errors in transfer.

Layer 3: Network
Connect networks. Provides routing through intermediary systems if necessary.

Layer 4: Transport
Provides data transfer between end processes.

Layer 5: Session
Manages the comms session from the application side.

Layer 6: Presentation
Ensures that data is represented in the appropriate format for different machines.

Layer 7: Application
Not the actual application itself but the part dealing with the network.

 
layers 1 through 4 transfers data through two systems.  layers 5 through 7 are 
application oriented services..

every connection between two computers on internet or on your network conn-
ect through tcp/ip.  every connection requires a client and a server it does not 
matter if its a http server a ftp server a internet program or a trojan server. it is
all transfered through tcp/ip . 
 
http stands for hyper text transfer protocol,   ftp stands for file transfer protocol.  
hyper text  is what transfers html to your pc to be displayed. hyper text markup 
launguage.  ftp is how you upload files to be displayed on a http server. or just 
to transfer files on your network. trojans work the same too..
 
a trojan and a http server works close to the same.   just oppiste.  ok you have 
a web browser like internet explorer on your pc.  that is a client. when you type 
a url.   you connect to another pc and connect to a http server.   then you down-
load the site,   and the browser compiles it and displays it.   well a trojan is the
other way around.  the server is installed on your system unknownly then some-
one connects with a client.   i am going to display a picture of an acctual trojan 
client here,    i am not going to release the name of it.  in case someone down-
loads it and gets in trouble with it all this information ihave on my site is just for 
that.   information not stealing or destroying others property.  its like learning to 
fight just to go into bars to fight and beat people up. its a childish state of mind. 
you should not use any of this against anyone else just for personal knowledge 
or to learn to protect yourself from idiotic kids.
 

 
as you can see there is a file manager to view,  upload,  delete,   and execute. 
there is tons more options in there. basicly a trojan is a remote control can be 
proggramed to do anything that is possible bye a pc.   anything possible.  you 
can use these on your own network too play around with or too have control of 
your pc. but never use it against someone.

hacking into a pc is simple to understand also.      every operating system has 
servers running all the time.  because for two pcs to communicate you need a 
client and a server. you can search up exploits for those servers running. a ex-
ploit is a weakness in a server. either buffer overflow which is just sending a 
large ammount of data to a server locking it up..   or a stack overflow.  some
times when you flood a server it restarts.  the stack is when a program first 
starts up and puts data into memory. 

well you run a port scanner on there ip address and you can see all the servers
running  you can also run a port scanner on your own ip address and find trojans
from that line you can see why this stuff exsists  the same stuff used to protect us
and help us  can be used against us.   like drugs used correctly is helpful
used wrong you get stoned off your ass. 

well anyways after you deploy a joint  (i mean) a exploit you connect your shell to 
there shell and run a shell code script. most common two is to get a list of files.  
or to upload and execute a program.  like a virus or a trojan so you can connect 
easyer later just by logging in. 

its usually not a ( operating system ) vunerbility however.   most of the time they 
aim for other servers like http or ftp servers.   etc.   the more servers you run on 
your pc.     the more likely your pc is hackable. not all pcs are hackable. basicly 
why i am saying this.        it is very important to download updates on operating 
systems. and other programs that connect online via tcp/ip. it patches the prog-
ram to block known exploits.
 
to see all the connections to servers you have,    or to see if a ( trojan server ) is 
waiting or active on your system,    and get the attackers ip address..   goto dos 
prompt by clicking start click run..  and type cmd.   press enter.    if it is a earlyer 
version of windows from xp,   then type command in the run box and press enter. 
ok in the dos prompt type  ( netstat -n )  and it will list active connections on your 
pc listing the ip address of the connection and the port it is connecting to.
 
heres something you can do to play with tcp/ip is  download this ftp server prog-
ram and download this ftp client program. and install them both and create user 
accounts on the ftp  then connect to it thru the ftp client.   you can either setup a 
network and wont need internet. or connect over internet to share files from one 
location too another. you can even do this on dialup. think about it when internet 
first started all it was.  was dial up internet.  or you can just connect locally. dont 
need internet or network.    just enter the ip address 127.0.0.1  that is local loop 
back ip. if you ran a httpserver on your pc the address would be http://127.0.0.1 
you can also download a free http server here at aprelium.com/abyssws.  

but to add a user on the ftp server is simple.  just click edit at top  click users.  in 
the right panel click the add button.    name it whatever you want.    check enable 
account  and check  password.  now on the left side  click shared folders.    click 
the add button.    and find the folder on the pc you want to share.    if its to use ftp 
with http then set it to the folder that holds the http files.    so then when someone 
uploads a file it updates the site.       click set as home dir and check the settings 
you want the user to have.    you can set it where all they can do it download files
or set it so they can delete  and upload files.