Ready-to-go phishing kits make it quick and easy for novice criminals to deploy new phishing sites and receive stolen credentials.

Phishing kits are typically ZIP files containing web pages, PHP scripts and images that convincingly impersonate genuine websites. Coupled with simple configuration files that make it easy to choose where stolen credentials are sent, criminals can upload and install a phishing site with relatively little technical knowledge. In most cases, the credentials stolen by these phishing sites are automatically emailed directly to the criminals who deploy the kits.

However, the criminals who originally authored these kits often include extra code that surreptitiously emails a copy of the stolen credentials to them. This allows a kit’s author to receive huge amounts of stolen credentials while other criminals are effectively deploying the kit on their behalf. This undesirable functionality is often hidden by obfuscating the kit’s source code, or by cleverly disguising the nefarious code to look benign. Some kits even hide code inside image files, where it is very unlikely to be noticed by any of the criminals who deploy the kits.

Netcraft has analysed thousands of phishing kits in detail and identified the most common techniques phishing kit authors use to ensure that they also receive a copy of any stolen credentials via email.

The Motivation Behind Creating Deceptive Phishing Kits

When a phishing kit is deployed, the resultant phishing site will convincingly impersonate a financial institution or other target in order to coax victims into submitting passwords, credit card numbers, addresses, or other credentials. These details will occasionally be logged on the server, but more often than not, are emailed directly to the criminals who install these phishing kits.