Type : Tutorial
Level : Easy
I think most of people who learn or already listen about computer security they will know about proxy server. I also already write post about Proxy server list and Proxy definitions who told about the type of proxy server and also a few website that inform the new and fresh proxy in the wild.
According to wikipedia a proxy server is a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource, available from a different server.
According to that definitions, below was the description of that condition by using illustration :
From the picture above :
Jonas will think that Charles was a proxy server and Charles also think that Jonas is a proxy server, because the proxy server will act as two of them. Every data you send or receive will always go through proxy server.
Also with proxy server we can save more time and packet data, because usually a proxy server have cache feature that will cache every requests. For example :
Charles open a webpage facebook.com, and then after 5 minutes Valentino also open facebook.com. When Charles open facebook.com maybe the webpage will open on 15 second because it was the first load and then the proxy server cached the data, when Valentino open facebook.com maybe it will open in 5 second, more faster than Charles, because the facebook.com data already stored on proxy server and Valentino will load the static page of facebook.com from proxy and load the dynamic data from facebook.com webpage.
Sure of course you can, on the internet there’s hundred or even thousand type of proxy server from the free one until paid and very expensive one are ready to download.
From that situation we know that “every person” were able to set up a proxy server and also the “bad people” can install the proxy server to gain a benefit from it.
Q : How the “bad people” gain a benefit from proxy server?
A : They set up free proxy server to intercept all the data come through or pass through the proxy server(doesn’t mean all free proxy will intercept the data).
Q : Who are the people that want to use that “malicious” type of proxy server?
A : Actually there’s no one know the proxy server was malicious or not, and according to Google search result in “free proxy server” about 23,5 million (click here) it’s almost impossible to detect one by one a malicious proxy server.
Illustrations(on my local computer) :
I’m open a webpage kaskus.us via a proxy server
What do you think about the picture above?
yes you’re right I’m running a proxy server and also activated listener on that server to capture all the plain data.
If you open a HTTP instead HTTPS(see the tutorial here), your data can be read easily by the attacker and they can gather your page credentials easily.
1. Act as caching server to make you load a webpage faster.
2. Masking your real IP address(anonymity).
3. (anyone can add more?I’LL put here)
1. All data came through this server, if this server was compromised it’s mean that all user use the server have possibility information / data theft.
2. If this proxy were located at ISP(Internet Service Provider), Campuss, School and there’s a bad employee or staff inside, it’s also possible data theft happen. And sometimes this bad guy will know you more than yourself
3. (anyone can add more?i’LL put here)
From the advantage and disadvantage above we know that in every advantages there’s always a disadvantage
1. If you want to use proxy make sure you use the trusted proxy. Usually user from China, some Arabic country, North Korea, etc they’re too desperate because of too many website blocked by their government firewall, so they forget to think about the security.
2. NEVER log in account using HTTP(http://blablabla.com/login.php) when you’re using a proxy(especially unknown proxy server), and If there’s no choice to do that, don’t forget to change your password ASAP.
3. Proxy server used by cracker to masking their ip address when performing the attack, make sure you didn’t fall into fake proxy trap because every proxy server habitually will record your real IP address.
4. Be wise to use this proxy service and also be careful….keep your eyes open
5. (anyone can add more here?)
Hope it’s useful