Last night I saw a funny service of the Hyenas on Italia 1 where there was talk of how it was possible to enter a wifi network and spy on the connected computers, without being noticed. What has been shown on television is all true only that the hyenas always do everything very easy and fast, when it is not really like that.
The reporter did not say, much less in depth both how "hackers" found the password of the Wifi network, and how they managed to read what the spied person was looking for on the internet.
But most importantly, they didn't explain very well how to protect themselves from these intrusion attempts.
In this article, since I felt stimulated by the topic, we make a global speech to understand what it means to sniff and capture network packets, how to spy on internet activities and also how you can get back, only theoretically, to enter a secure wifi network .
READ ALSO: Verify LAN / Wifi network security by simulating hacker attacks
Obviously there is a remedy for everything and protecting yourself is easy, the important thing is to enter the mentality that everyone is excellent to spy on and what you do on the internet can be very interesting for another person, even unknown.
So never think that, since I'm nobody, I will never be spied on.
To avoid a too long and complicated speech, I will be very brief and schematic, going in order and referring any questions and insights to the comments.
1) To begin with, whoever has a wifi connection keeps us from connecting to the internet for free, stealing bandwidth without paying.
To protect yourself from those who connect to the wifi network by stealing the connection there are various methods that I have already written about.
Open networks are freely accessible and it does not take any password to enter and surf the internet.
Encrypted networks are protected with a password and are of two types: WEP connections ( Wired Equivalent Privacy ), very simple to crack with tools freely available on the internet (of which we will speak shortly).
For this reason, WEP should no longer be used, as we have seen, when you install a wireless network at home, you must set up a secure connection with WPA ( Wi-Fi Protected Access ) or WPA2 key .
2) Finding open or vulnerable wifi networks, as shown in the TV service, is very easy because you just have to walk around, with your wifi cellphone or laptop, for the buildings in your neighborhood and draw up a network map.
As seen, there are programs that automatically draw the network point map and connection strength.
Even better there are programs like Inssider that allow you to find the best wifi network .
It is not necessary to be inside the wireless network to use Inssider; just run it, select the wireless network interface from the drop-down list and press the Start Scanning button.
The information found shows the model of the wireless router, the name of the network (called SSID), the signal strength and the type of protection used (WEP or WPA).
The model and brand of the router is important information because each router has a default password to access the network configuration panel.
Fortunately, to access the router configuration, you must first enter the network and then know the protection key (if there is no key, goodbye!).
3) To find network passwords, it doesn't take a genius but it's not as simple as they want it to look.
Meanwhile, programs such as WirelessKeyView (see network password recovery article), which serve only to find the password stored in the computer, if you have forgotten it, have nothing to do with it.
There are no programs that recover passwords instantly.
The procedure to find out the key and therefore the password of a wifi network protected with WPA or WPA2 is the so-called bruteforce, that is, a scan of thousands of possible combinations and common passwords.
What is important to know now is that, by setting up a WPA2 protection, with a strong password that is not a word that makes sense (like stellina or torino or francesca) and that also contains numbers (like 1centero323), the wifi network is more difficult to violate .
4) Once you enter a network, you can monitor and spy on what is done on the internet from all connected PCs, in real time.
It is not a question of entering other people's computers and seeing shared folders (which is absolutely feasible, however) but of understanding which sites are surfed by the other connected PCs, what they are looking for on Google and maybe even the passwords they enter.
To try sniffing at home, if you have a wifi network and two computers, you can try using one pc to monitor the other.
On the same network you can sniff, intercept and capture the network packets on a Windows PC with a very famous free program called Wireshark of which I have written a short introductory guide.
Alternatively you can use another great free program for all versions of Windows called Netwalk which as a graphical interface is much more beautiful and clear.
Both programs include the WinpCap network driver (otherwise Windows, unlike Linux, does not allow you to use the network card in "promiscuous" mode).
On Wireshark, just press the Interface List link, choose the wifi network that is used by the two computers and then press Start to start capturing the network packets exchanged on the internet .
On Netwalk instead you can start sniffing the network and intercepting the packets by going to Monitor -> Switch Adapter to choose the network connection; then press the green play button to start capturing packages that can be saved to a file.
Netwalk gives much more information on the net and is among the best programs for analysis and monitoring.
Netwalk is beautiful because it shows, graphically the intercepted packets reporting the reports of the sites visited during a capture session.
While capturing packets a lot of items appear in a list that updates every second.
The most interesting information is that of the HTTP protocol, where, when writing GET, it is possible that, among other things, the search keys used on Google or the passwords to access the websites.
You will also see internet traffic from the PC on which Wireshark is running.
In Wireshark and Netwalk you can set the filter to see only the HTTP packets and better identify the information on web traffic.
In another article we talk about other tools to sniff the net and see sites visited and searches done on the internet, intercepting traffic .
For maximum protection, it is important, when connecting outside the home to public wifi networks, that passwords are never entered on sites whose page does not start for https.
HTTPS connections are safe and secure and cannot be intercepted or captured by programs such as Wireshark.
Facebook, Twitter, banking sites and sites for reading emails are always protected in HTTPS.
The type of the Hyenas, if he had monitored me, would never have been able to discover the Facebook password because I connect to Facebook with a secure connection, in HTTPS, always.
Also consider that installing a firewall on your computer puts a shield that can prevent other computers (even on the same network) from "seeing" internet traffic.
