A new phishing kit uses a custom web font to implement a substitution cipher in its efforts to target customers of a major U.S. bank.

Researchers at Proofpoint first came across the unnamed phishing kit in May 2018. The landing page leverages stolen branding to steal users’ credentials for a major retail bank, and the source code includes encoded display text.

Digging further, the researchers determined that the base64-encoded woff and woff2 files were the only loaded fonts in the template. They then observed that the kit uses a custom web font file to render the ciphertext as plaintext, which helps it evade detection and conceals its activity from victims.

A Busy Year for Phishing Kits

Phishing kits were a prominent threat in 2018. Check Point came across a new phishing kit on the dark web in April 2018. The template provided would-be criminals with a backend interface for creating convincing fake retail product pages and managing their entire campaign. A few months later, Akamai analyzed a zip file containing phishing kits. One of the five directories analyzed by Akamai had code to target a bank located in the Southern and Midwestern states.

Several new malicious document builders have also emerged over the past two years. In October 2017, Proofpoint discovered ThreadKit, a Microsoft Office document exploit builder kit used for distributing Formbook, Loki Bot and other malware. Just a few months later, the security firm came across LCG Kit, another weaponized document builder service.

How to Defend Against Phishing Attacks

Security professionals can help defend their organizations against phishing attacks by proactively running phishing simulations to test their employees’ security awareness. They should also conduct penetration tests to analyze other aspects of their organizations’ email security.