This lab examines the internal structure of a typical phishing kit used for credential harvesting. The goal is not to operate the kit but to understand how these packages are assembled and how they move stolen data.
The sample kit was obtained from a public repository where previously collected phishing infrastructure had been archived. Analysis was performed locally and in isolation.
Most phishing kits follow a predictable structure. The one used in this lab contained the following components:
- A landing page that visually imitates the target service.
- A login form capturing usernames and passwords.
- A backend script that processes the submitted credentials.
- A mechanism for sending stolen data to the attacker.
The landing page was a static HTML file combined with copied styling assets from the legitimate service. In many kits the visual elements are cloned directly from the real website in order to reduce suspicion.
When credentials are entered, the form sends a POST request to a backend script. In this sample the handler was written in PHP and stored the credentials before forwarding the victim to the legitimate site.
Exfiltration methods vary. In this kit the credentials were forwarded via email to an attacker controlled mailbox. Other kits store them in text files or forward them to a remote server.
Looking at the code revealed several patterns that defenders can watch for:
- Suspicious POST handlers capturing login fields.
- Outbound email calls embedded in form handlers.
- Redirect logic designed to hide the phishing step.
Understanding these structures helps when analyzing suspicious web content or investigating incidents. Even when the visual design changes, the backend mechanics of many phishing kits remain surprisingly similar.