What is Formjacking?

Formjacking is a cyberattack where malicious code is injected into a website form to steal data as users type or submit it. Attackers often target checkout pages, login forms, donation forms, booking forms, and any web form that collects payment or personal information.

In simple terms, formjacking works like a hidden card skimmer on a website. The form may look normal to the customer, and the payment may still go through, but a copy of the submitted data is silently sent to the attacker.

How Formjacking Works

Formjacking usually starts when attackers compromise a website, a plugin, a third-party script, or a poorly secured admin account. They then add JavaScript that listens for form entries or intercepts submitted data.

The stolen information may include names, addresses, phone numbers, email addresses, login credentials, payment card numbers, CVV codes, and billing details. Because the legitimate website continues to function, both users and businesses may not notice the attack immediately.

Formjacking is commonly associated with web skimming groups and supply chain attacks. Instead of attacking every visitor directly, attackers compromise one trusted website or script and collect data from many users at once.

Why Formjacking Is Dangerous

Formjacking is dangerous because it abuses trust. Customers believe they are entering data into a legitimate business website, while the attacker operates invisibly in the background.

For businesses, the impact can include data breaches, payment fraud, regulatory exposure, customer churn, and reputational damage. Even if the malicious code comes through a third-party component, the affected organization may still need to investigate, notify stakeholders, and strengthen controls.

Common Signs of Formjacking

Formjacking can be difficult to detect without technical monitoring, but warning signs may include:

• Unexpected JavaScript changes on checkout or login pages
• Unknown external domains loading on sensitive forms
• Customer reports of payment fraud after using the website
• Security alerts from web application scanners or file integrity tools
• Unusual administrator activity or plugin changes

How Businesses Can Reduce Formjacking Risk

Organizations can reduce formjacking risk by protecting both the website and the devices used to manage it. Websites should use strong access controls, regular patching, code reviews, content security policies, script integrity checks, and continuous monitoring for unauthorized changes.

Businesses should also secure administrator endpoints, because stolen credentials and compromised devices can lead to website tampering. Unified endpoint management platforms such as Hexnode can help enforce device security policies, manage browser and app access, and reduce exposure from unmanaged endpoints.