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Free_Wi-Fi … how nice it is to see such an alert on the screen of a smartphone or other gadget when you sat down to relax in a cafe in a shopping center or airport before departure. So the man is arranged that pulls him to everything free. However, everyone knows where free cheese is most often. What are the dangers of free wifi?
It has long been no secret (at least for knowledgeable people) that the operators of open networks with Internet access can easily intercept all traffic going through them and receive various information in this way, including what you are looking for and what resources you visit. It’s good if they simply pass it on to advertisers in order to study the demand for goods and services, and that’s all there is to it, but these are far from all the dangers that await the owners of electronic devices who are eager for freebies. What else is wrong?
Recently, a law was passed in the Russian Federation designed to secure open access points in public places through mandatory authorization using a mobile phone or social networks. But, as often happens, “something went wrong” and a seemingly good business turned into new vulnerabilities that play on the intricacies of the human soul. As a result, a small project was born that fully demonstrates the limitless gullibility of the vast majority of Homo Sapiens representatives. So, first things first.
What kind of beast is this?
The beasts were invented and embodied in iron by our Chinese colleagues. More precisely, they built the skeleton of the most predatory beast, which we will wear in sheep's clothing. His name is the ESP8266 controller, repeatedly mentioned on the pages of Hacker and GitHub. In our project, we will use it as a standalone access point and web server. The device will raise an access point with the name Free_Wifi that does not contain a password, while most smartphones and other devices will send their owners a notification asking them to connect to an open Wi-Fi network, even if they did not view the list of available networks. This has been tested on Android 9 and iOS latest version. So, a gullible user, not really relying on intuition and common sense, clicks on a drop-down notification with a very tempting offer and gets to the registration page (without having to open a browser). This window will appear on the screen.
Here we see the standard welcome page of open access points, offering to log in using e-mail, password and phone number or immediately enter the authorization code, if any. The victim (as a rule, without hesitation) enters data, after which he receives a notification that he needs to wait for an SMS message with an authorization code, and all the data entered by the victim is safely merged onto the device’s SD card, simultaneously displayed on the OLED display.
So, our device works in the mode of a fake access point, which has an attractive name and forces nearby devices to pay attention to the invitation to connect, but actually just merges user credentials.
So, what is next?
But then the fun begins. In the simplest case, we will have a supposedly valid email address and phone number. In the best case, we will get a certain password as a bonus – perhaps one of those that this person uses.
Do you often use different passwords for different services? The question is most likely rhetorical. But even without a valid password, you can already draw conclusions about a person’s preferences and level of awareness. And the email address and phone number – this is at least some kind of information that can play a big role in further attacks. There’s enough imagination: from sending letters and SMS with advertising of nearby establishments to breaking into mail, social networks and deanonymizing a person … At a minimum, this method will allow you to find out the number and soap of a girl from a neighboring entrance.
In general, we have clearly seen that open networks can be very unsafe.
The birth of the beast
As I said, we will use ESP8266 NodeMCU or ESP32 (for 32 you will have to correct the code), these controllers work identically. We are equipped with a soldering iron, a breadboard, tools. Our device also uses a microSD card adapter and an OLED display of 128 by 32 pixels with an SSD1306 controller and i2C interface. We also need a buzzer (tweeter speaker from the old system unit). So, everyone has prepared. We take the circuit, which is shown in the following picture, and proceed to the assembly of the beast. You can solder, you can connect just on the breadboard, the essence of this will not change.
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