Fake CAPTCHA PDFs: Cybercriminals Are Using GoDaddy, and More to Spread Lumma Stealer

Cybercriminals constantly evolve their tactics to deceive victims and steal sensitive information. The latest phishing campaign leveraging fake CAPTCHA PDFs is a highly sophisticated attack that tricks users into installing Lumma Stealer, a powerful malware designed to steal login credentials, financial data, and browser cookies.

Researchers have discovered that hackers are abusing legitimate platforms like Webflow, GoDaddy, Wix, and Strikingly to host these malicious PDFs. Attackers further manipulate search engines using SEO techniques, ensuring these files appear as top search results for unsuspecting users.

This article will cover:

• How cybercriminals are distributing fake CAPTCHA PDFs
• The role of Webflow, GoDaddy, and other domain-hosting platforms
• The evolution of Lumma Stealer and its impact on global industries
• Steps to protect yourself from phishing and malware attacks

Let’s dive deep into this cyber threat and uncover how you can stay safe.

How Fake CAPTCHA PDFs Are Spreading Malware

Exploiting Webflow, GoDaddy, and Other Hosting Platforms

Cybercriminals are leveraging legitimate website-building and hosting platforms to distribute malicious PDFs. According to Netskope Threat Labs, over 260 unique domains have been identified hosting more than 5,000 phishing PDFs, many of which reside on:

• Webflow (Primary host for phishing PDFs)
• GoDaddy, Strikingly, Wix, and Fastly (Secondary hosts exploited by hackers)
• Online PDF repositories (e.g., PDFCOFFEE, PDF4PRO, Internet Archive)

How Hackers Use These Platforms:

1. They upload seemingly harmless PDF files to legitimate-looking websites.
2. These PDFs are optimized with SEO techniques so they appear in search results.
3. Users searching for common topics like financial reports, software manuals, or academic documents may accidentally download these infected files.
4. The PDFs contain a fake CAPTCHA image, prompting the victim to “verify” their identity.
5. Clicking the CAPTCHA triggers a hidden PowerShell script, which downloads and installs the Lumma Stealer malware.

Because Webflow and similar platforms are trusted by users, many people fail to question the authenticity of these PDFs before opening them.

• The Role of Fake CAPTCHAs like Fake Captcha PDFs in Malware Distribution

Fake CAPTCHAs are a clever deception tactic that plays on user expectations. CAPTCHAs are commonly used to verify that a visitor is not a bot, so most users don’t suspect any foul play when they encounter them.

Here’s how fake CAPTCHA PDFs deliver malware:

1. A victim downloads an infected PDF document from a phishing website.
2. Upon opening the file, they see a CAPTCHA verification request.
3. The CAPTCHA is just an image with an embedded malicious link.
4. Clicking on it runs a hidden PowerShell command, silently executing Lumma Stealer in the background.

Unlike traditional phishing attacks that request passwords outright, this method makes the victim unknowingly install the malware themselves, making it far harder to detect.

How SEO Manipulation Fuels Malware Distribution

Hackers are weaponizing SEO (Search Engine Optimization) to ensure their Fake Captcha PDFs rank high on Google and Bing. They do this by:

✔ Using high-volume search terms related to business, finance, and academia
✔ Embedding popular keywords to increase visibility in search results
✔ Posting PDFs on authoritative-looking sites to boost credibility

The Risk of YouTube SEO Manipulation

Beyond search engines, attackers use YouTube to distribute malware. Malicious links are often embedded:

❌ In video descriptions
❌ As pinned comments
❌ In tutorial videos advertising free software downloads

Cybercriminals hijack previously trusted YouTube accounts and upload videos that appear genuine. These videos trick users into downloading files that contain Lumma Stealer or redirect them to infected sites.

The Widespread Impact of Lumma Stealer Malware

Lumma Stealer is a malware-as-a-service (MaaS) tool, allowing hackers to buy access and deploy it with ease. Since mid-2024, the phishing campaign has targeted:

• Financial services (Banking, investment firms)
• Technology firms (Software developers, cybersecurity companies)
• Manufacturing and industrial sectors

More than 7,000 users across 1,150 organizations have been affected, primarily in North America, Asia, and Southern Europe.

1. What Data Does Lumma Stealer Collect?

Once installed, Lumma Stealer extracts:

✔ Login credentials (Emails, passwords, social media accounts)
✔ Browser cookies and session tokens (Allowing hackers to bypass 2FA)
✔ Credit card details and online banking credentials
✔ Cryptocurrency wallet data

2. Evolution of Lumma Stealer

Hackers have found new ways to distribute Lumma Stealer, including:

• Fake software downloads (E.g., a cracked version of Total Commander)
• Malicious Roblox game installers
• Leaky[.]pro hacking forum (Distributing stolen credentials for free)

How to Protect Yourself from Fake CAPTCHA PDFs Attacks

1. Recognize the Red Flags

🚨 Never trust CAPTCHA verifications inside PDFs.
🚨 Avoid opening PDFs from unknown sources.
🚨 Be cautious of sudden pop-ups requesting logins or downloads.

2. Verify the Source Before Downloading

🔹 Always check if a file source is legitimate before opening it.
🔹 Avoid downloading PDFs from random online repositories.

3. Strengthen Your Security Defenses

✔ Keep antivirus software up to date.
✔ Enable two-factor authentication (2FA) for all sensitive accounts.
✔ Use web browser extensions that warn against suspicious websites.

4. Be Cautious on YouTube

🔹 Avoid clicking links in video descriptions unless the uploader is verified.
🔹 Watch out for “free software” download offers—they are often malware traps.

Final Thoughts

The fake CAPTCHA PDFs phishing campaign is one of the most advanced cybersecurity threats in recent months. By exploiting SEO, file-sharing platforms, and social media, hackers are tricking thousands of users into installing Lumma Stealer malware.

To stay safe:
✅ Always verify file sources before downloading.
✅ Never interact with CAPTCHAs embedded inside PDFs.
✅ Use strong cybersecurity measures to protect your data.

💡 Stay vigilant and help spread awareness to keep others safe!