View attachment 8294
Tampering Antifraud Requests using Burp Suite
Lots of people have been requesting me for some time now some more guides on how to use
Burp. So I figured Id finally cave and drop some knowledge on one of the most
powerful tools in your digital arsenal.
Burp is a versatile tool with hundreds of nifty features that can be used beyond just assessing sites - you can check
vulnerabilities find hidden endpoints, manipulate web traffic and fuck with those
pesky antifraud systems blocking your cards. When you know what you're doing, the possibilities are extensive.
Intercepting Requests
See when you browse any website, theres a constant back-and-forth conversation happening. Your browser (the frontend) sends requests to the website's servers (the backend) which processes them and sends back responses. Its a digital conversation where your browser requests to view products or make purchases, and the server responds accordingly.
Burp Suite plants itself right in the middle of this conversation as a
proxy. It's digital eavesdropping – you see every request leaving your browser and every response coming back. More importantly you can pause this conversation, edit whats being transmitted and then let it continue. The server has no fucking clue you just rewrote the script.
This matters because when shopping online your browser isn't just talking to the main website. Its also sending data to hidden
antifraud systems like
Stripe Radar or
Forter that analyze whether you're legitimate or some
bot-using scammer. With
Burp, you can intercept and manipulate both types of traffic – the main site requests and the sneaky antifraud callbacks happening behind the scenes.
Bypassing CVV Requirement via Intercept
One common application of
Burp especially among autistic Binners, is forcing sites to accept cards without CVV. Binners generate cards in bulk and test them using public checkers but most sites require CVV, which is why
Burp became such a valuable tool.
Heres the dirty little secret: When you submit payment info at checkout your browser sends a POST request containing all your card details – number, expiry CVV, the works. Using
Burp's Intercept feature you can catch this request before it reaches the server and edit that shit however you want.
The trick is to either remove the CVV field entirely:
Code:
{"card_number":"4111111111111111","expiry":"12/25""billing_zip":"10001"}
Or replace it with an empty value:
Code:
{"card_number":"4111111111111111","expiry":"12/25""cvv":"","billing_zip":"10001"}
If the merchants backend validation is garbage (and you'd be amazed how many major retailers fuck this up) the payment might still process. Some payment gateways configure CVV as "optional" rather than required, and lazy developers often dont enforce proper validation. Heck, I've seen shops before where you can even tamper and change the prices of the items you are checking out.
Other major retailers have similar
vulnerabilities that Binners exploit to use their generated cards without any CVVs.
Altering Antifraud Request
Now that you understand the basics of interception let's step it up. We all know modern antifraud systems are
sneaky motherfuckers. They inject JavaScript code into the pages you browse, silently collecting mountains of data about you. These scripts track everything from your device configuration to how you move your mouse.
Heres what these scripts typically gather:
- Browser fingerprints (user agent screen resolution, installed fonts)
- Hardware details (GPU info via WebGL rendering CPU cores)
- Mouse movements and click patterns (speed, jitter natural vs. bot-like paths)
- Typing rhythm (how fast you enter data, pauses between keystrokes)
- Whether you're using a headless browser or automation tools (Selenium etc.)
All this data gets packaged and sent to their servers (like m.stripe.com for
Stripe or forter.com endpoints) where AI systems decide if youre legit or sketchy.
These systems know their data can be tampered with, so they try to hide it from prying eyes. They'll:
- Base64 encode their payloads
- Use character swapping (like replacing a' with x' and vice versa)
- Obfuscate their JavaScript code
- Split data across multiple requests
- Use custom encoding schemes
But heres the dirty truth: security through obscurity is about as effective as that 414720 you bought for $1. These systems must send data in a format your browser can process which means it's there for the taking if you know where to look.
Practical Example: Riskified in Booking.com
Lets get our hands dirty with
Riskified, one of the more
notorious fraud prevention systems that's been cockblocking carders left and right. Unlike some half-assed security measures this one actually has some teeth to it.
First, we need to set up interception rules in
Burp Suite:
- Go to Proxy > Options > Intercept Client Requests
- Add a rule: AND domain name matches c.riskified.com
- Disable response interception
Now browse around the site and pick a flight and try getting to the checkout page and it will most likely connect first to:
After connecting here, it downloads the JS needed to fingerprint your system. This isnt casual data collection – it's a full digital cavity search that attempts to send everything about you to:
c.riskified.com
Since weve set up interception the fingerprint won't be sent to
Riskifieds servers. If you check the HTTP logs panel, you'll see it trying to send an
obfuscated payload containing your digital DNA:
Deobfuscation
Anti-fraud sites obfuscate your fingerprint because if they didnt tampering would be child's play. Its like hiding your house key – sure, it's still there but at least make the thief work for it.
Desofuscar el código requiere habilidad, pero no es ciencia espacial. Solo necesitas aplicar ingeniería inversa a cómo el JavaScript creó la carga útil. Si tu coeficiente intelectual es inferior a 70, consulta con una IA. Y si te sientes un sabelotodo pensando que solo es Base64 para Riskified (aunque muchos solo usan codificación Base64), no lo es:
Pero ya me conocen, los quiero mucho, así que para esta demostración desarrollé una herramienta que ayuda a desofuscar las huellas dactilares de las soluciones antifraude más populares. Para esta demostración, he habilitado
Riskified , pero pronto añadiré la mayoría de los proveedores antifraude.
binx.cc
Entonces, para facilitar las cosas, diríjase a la herramienta de desofuscación antifraude en BinX y seleccione
Riskified y pegue nuestra carga útil interceptada.
Después de la desofuscación, los datos de sus huellas dactilares aparecen como un libro abierto.
[CÓDIGO]
{
"latitud": 37.7749,
"zona horaria": 240,
"marca de tiempo": "1689452187394",
"cart_id": "7629384105",
"id_tienda": "cf.bstatic.com",
"referente": "
https://secure.booking.com/",
"href": "
https://cf.bstatic.com/static/tag_c...a077563c1795a773c91150dd19adefe98d13fd65.html",
"riskified_cookie": "p8jkl352qxnrtyuvcbm7fds9ghzwe6",
"profundidad_de_color": 24,
"id_de_página": "9xzp4r",
"tienda": "
www.booking.com",
"concurrencia_de_hardware": 8,
"has_touch": verdadero,
"longitud_del_historial": 7,
"document_title": "Booking.com",
"console_error": "console.memory no está definido",
"battery_error": "Error al obtener la batería()",
"estado_inicial_de_cookie_0": "https",
"estado_inicial_de_cookie_1": "persistente",
"navegador": {
"productsub": "20030107",
"is_opr": verdadero,
"is_firefox": falso,
"ev_len": 42
},
"os": {
"cpu": "Windows NT 10.0",
"plataforma": "Win32"
},
"webgl": {
"proveedor": "Google Inc.",
"renderer": "ÁNGULO (Intel, Intel® UHD Graphics 620, OpenGL 4.5)"
},
"resolución": {
"dpr": 1.5,
"pantalla": 1080,
"pantalla": 1920,
"disponible": 1040,
"disponible": 1920,
"interior": 900,
"interior": 1600,
"exterior": 1040,
"exterior": 1920
},
"date_string": "Vie 25 Mar 2025 14:23:07 GMT-0400 (Hora de verano del este)",
"intl": {
"configuración regional": "en-GB",
"num_sys": "latn",
"cal": "gregorio",
"tz": "América/Nueva_York"
},
"downlink_error": "navigator.connection no está definido",
"nav_plu": "Complemento PDF de Chrome, Visor PDF de Chrome, Cliente nativo",
"nav_lang": "en-GB",
"datos_del_idioma_de_la_página": {
"page_language": "es",
"tiene_traducción": verdadero
},
"de incógnito": {
"safari": cierto,
"cuota de cromo": 120,
"service_worker_undefined": falso,
"is_brave": verdadero
}
}
[/CÓDIGO]
Luego, puede realizar modificaciones estratégicas para aumentar
los factores de confianza y alinearlos con su perfil objetivo:
Texto oculto: no se puede citar.
Una vez que hayas realizado los cambios, vuelve a ofuscar esa mierda y reemplaza la carga útil en tu panel de intercepción y REENVÍA la solicitud.
Este proceso vincula tu huella digital falsificada con tu cookie. El sistema cree que eres un
cliente legítimo más , no el estafador digital que realmente eres.
Conclusión
Manipular los sistemas antifraude con
Burp Suite es como tener un kit de camuflaje digital. No solo cambias tu apariencia, sino que también alteras lo que ven las cámaras de seguridad. Al colocar
Burp entre tu navegador y estos sistemas, puedes introducir la huella digital que quieras, sin siquiera usar un antidetección.
El éxito depende de comprender exactamente qué recopilan estos sistemas y cómo lo interpretan. Analice sus registros
de Burp para estudiar las solicitudes antifraude antes de manipularlas. Busque patrones en los datos JSON. Cuanto mejor comprenda lo que revisan, con mayor precisión podrá manipularlo.
Recuerde: el engaño digital eficaz no se trata de invisibilidad, se trata de parecer tan normal que nunca piensen en mirar dos veces.
Tengan en cuenta que apenas hemos explorado superficialmente las posibilidades de
Burp Suite . Esta herramienta excepcional cuenta con docenas de módulos y cientos de funciones que ni siquiera he mencionado, desde el escaneo automatizado hasta la detección de vulnerabilidades SQLi y el fuzzing de endpoints. Es una herramienta compleja que recompensa a quienes dedican tiempo a dominarla. Abordaré técnicas más avanzadas en futuras guías.
Hasta pronto. d0ctrina fuera.