Direito - Unip - DNA 2,03/08

quinta-feira, 1 de junho de 2023

BYOPPP - Build Your Own Privacy Protection Proxy

I have read a blog post, where you can build your own privacy proxy server built on Raspberry PI. The post got me thinking about how I can use this to protect my privacy on my Android phone, and also get rid of those annoying ads.

Since I own a Samsung Galaxy S3 LTE with Android 4.3 (with a HW based Knox counter), rooting the phone now means you break Knox, and loose warranty. Past the point of no return ...

This means I have to solve this without root. Luckily newer Androids support VPN without rooting, but setting a mandatory system-wide proxy is still not possible without root.

But thanks to some iptables magic and Privoxy, this is not a problem anymore :)

The ingredients to build your own privacy protection proxy:

One (or more) cheap VPS server(s)
a decent VPN program
Privoxy
iptables

VPS server

To get the cheap VPS server, I recommend using Amazon EC2, but choose whatever you like. The micro instance is very cheap (or even free), and has totally enough resources for this task. I'm using the Ubuntu free tier now and it works like a charm. And last but not least Amazon has two-factor authentication! You can set up an Ubuntu server under 10 minutes. Use the AWS region nearest to you, e.g. I choose EU - Ireland.

VPN

For the VPN program, I recommend the free version of the OpenVPN AS (EDIT: be sure to use OpenVPN AS 2.0.6 or later, both on the server and the client). Easy to set-up quick start guide is here, GUI based configuration, and one-click client installer for Android, iOS, Windows, Linux, OSX. The Ubuntu installer packages are here.

The most important settings:

I prefer to use the TCP 443 and UDP 53 ports for my OpenVPN setup, and let the user guess why.
For good performance, UDP is preferred over TCP.
VPN mode is Layer 3 (routing/NAT).
Don't forget to allow the configured VPN ports in the AWS firewall (security groups).

Other VPN settings:

Should VPN clients have access to private subnets (non-public networks on the server side)? - Yes
Should client Internet traffic be routed through the VPN? - Yes

Privoxy

The next component we have to install and configure is Privoxy. As usual, "apt-get install privoxy" just works. The next step is to configure privoxy via /etc/privoxy/config file, there are two options to change:

listen-address your.ip.add.ress:8118
accept-intercepted-requests 1

Beware not to allow everyone accessing your Privoxy server in the AWS EC2 security groups, be sure it is reachable only to VPN users!

After everything is set, start privoxy with "service privoxy start", and add it to the autostart "update-rc.d privoxy defaults".

Iptables

And the final step is to configure your iptables chain to forward every web traffic from the VPN clients to the Privoxy server:

iptables -t nat -A PREROUTING -s 5.5.0.0/16 -p tcp -m multiport --dports 80,8080,81 -j DNAT --to-destination your.ip.add.ress:8118

Optionally you can block access to all other ports as well, and what does not go through your Privoxy won't be reachable.

Based on your Linux distribution and preference, you might make this rule persistent.

Final test

Now you can connect to the VPN server from your Android device.

After logging in from a client, you get the following nice packages to install on your device:

After connecting, the final results can be seen in the following screenshots. And yes, there is a reason I chose Angry Birds as an example.

Angry Birds without Privoxy

Angry Birds with Privoxy

Stupid flashlight app with ad

Stupid flashlight app with Privoxy

Spoiler alert

If you are afraid of NSA tracking you, this post is not for you. If you want to achieve IP layer anonymity, this post is not for you. As long as you are the only one using that service, it should be trivial to see what could possibly go wrong with that.

Known issues

Whenever the Internet connection (Wifi, 3G) drops, the VPN connection drops as well, and your privacy is gone ...

Sites breaking your privacy through SSL can still do that as long as the domain is not in the Privoxy blacklist.

Additional recommendation

If you are using OSX or Windows, I can recommend Aviator to be used as your default browser. It is just great, give it a try!

PS: There are also some adblock apps removed from the official store which can block some ads, but you have to configure a proxy for every WiFi connection you use, and it is not working over 3G.

Related word

quarta-feira, 31 de maio de 2023

FOOTPRITING AND INFORMATION GATHERING USED IN HACKING

WHAT IS FOOTPRITING AND INFORMATION GATHERING IN HACKING?

Footpriting is the technique used for gathering information about computer systems and the entities they belongs too.
To get this information, a hacker might use various tools and technologies.

Basically it is the first step where hacker gather as much information as possible to find the way for cracking the whole system or target or atleast decide what types of attacks will be more suitable for the target.

Footpriting can be both passive and active.

Reviewing a company's website is an example of passive footprinting,
whereas attempting to gain access to sensititve information through social engineering is an example of active information gathering.

During this phase hacking, a hacker can collect the following information>- Domain name
-IP Addresses
-Namespaces
-Employee information
-Phone numbers
-E-mails
Job information

Tip-You can use http://www.whois.com/ website to get detailed information about a domain name information including its owner,its registrar, date of registration, expiry, name servers owner's contact information etc.

Use of Footprinting & Information Gathering in People Searching-
Now a days its very easy to find anyone with his/her full name in social media sites like Facebook, Instragram,Twitter,Linkdedin to gather information about date of birth,birthplace, real photos, education detail, hobbies, relationship status etc.

There are several sites like PIPL,PeekYou, Transport Sites such as mptransport,uptransport etc and Job placement Sites such as Shine.com,Naukari.com , Monster.com etc which are very useful for hacker to collect information about anyone.
Hacker collect the information about you from your Resume which you uploaded on job placement site for seeking a job as well as hacker collect the information from your vehicle number also from transport sites to know about the owner of vehicle, adderess etc then after they make plan how to attack on victim to earn money after know about him/her from collecting information.

INFORMATION GATHERING-It is the process of collecting the information from different places about any individual company,organization, server, ip address or person.
Most of the hacker spend his time in this process.

Information gathering plays a vital role for both investigating and attacking purposes.This is one of the best way to collect victim data and find the vulnerability and loopholes to get unauthorized modifications,deletion and unauthorized access.

Continue reading

LEGALITY OF ETHICAL HACKING

Why ethical hacking?

Legality of Ehical Hacking

Ethical hacking is legal if the hacker abides by the rules stipulated in above section on the definition of ethical hacking.

Ethical hacking is not legal for black hat hackers.They gain unauthorized access over a computer system or networks for money extortion.

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OpenVAS

"OpenVAS stands for Open Vulnerability Assessment System and is a network security scanner with associated tools like a graphical user front-end. The core is a server component with a set of network vulnerability tests (NVTs) to detect security problems in remote systems and applications." read more...

Website: http://www.openvas.org