Researchers have detailed a new proof-of-concept attack showing how adversaries can use AI-generated summaries to push ransomware and other malicious commands directly to unsuspecting users.
How ClickFix Works
The tactic, called ClickFix, manipulates victims into running self-sabotaging commands under the guise of resolving an error or fixing an issue. In past incidents, attackers impersonated Booking.com or injected fake reCAPTCHA prompts, tricking users into pasting commands into the Windows Run prompt. In one campaign, over 100 automotive dealership websites briefly displayed malicious instructions to visitors.
The new proof-of-concept from CloudSEK takes ClickFix a step further by abusing AI summarization tools. Researchers showed how attackers could embed malicious instructions into HTML content using techniques like invisible white-on-white text, zero-width characters, tiny font sizes, and off-screen text placement. While these elements remain invisible to a human reader, they dominate an AI model’s context window, surfacing prominently in generated summaries.
When an AI assistant, browser extension, or email summarizer processes the content, the summary may end up displaying the hidden payload as if it were legitimate advice. CloudSEK demonstrated how such a summary could instruct a victim to paste a PowerShell command into the Run prompt, initiating a ransomware infection. Because the instructions appear to come from the AI summarizer itself, not an external attacker, the victim is far less likely to question them.
CSS Obfuscation and Prompt Overload
The success of this attack relies on a blend of CSS obfuscation and what researchers call “prompt overdose.” By repeating hidden payloads multiple times in the HTML, the attacker ensures that the malicious instructions outweigh legitimate context during summarization.
This manipulation effectively turns the AI tool from a passive summarizer into an active participant in the social engineering chain. What looks like a harmless article, blog post, or email to a human user may, once summarized, output only the attacker’s malicious instructions.
Defensive Recommendations
CloudSEK’s guidance for defenders focuses on improving how AI pipelines preprocess and handle content:
- Summarizers should normalize or strip suspicious CSS attributes before processing inputs.
- Enterprises should implement prompt sanitizers that filter hidden payloads before they reach summarization models.
- Detection rules should be created for repeated, hidden text patterns that could dominate AI outputs.
- Organizations deploying internal AI summarizers should enforce strict preprocessing policies at gateways, content systems, and browser extensions.
Most importantly, researchers emphasize the need for enterprise-level AI policy enforcement and secure design patterns that prevent AI outputs from triggering sensitive actions without explicit user approval.
How Can Netizen Help?
Founded in 2013, Netizen is an award-winning technology firm that develops and leverages cutting-edge solutions to create a more secure, integrated, and automated digital environment for government, defense, and commercial clients worldwide. Our innovative solutions transform complex cybersecurity and technology challenges into strategic advantages by delivering mission-critical capabilities that safeguard and optimize clients’ digital infrastructure. One example of this is our popular “CISO-as-a-Service” offering that enables organizations of any size to access executive level cybersecurity expertise at a fraction of the cost of hiring internally.
Netizen also operates a state-of-the-art 24x7x365 Security Operations Center (SOC) that delivers comprehensive cybersecurity monitoring solutions for defense, government, and commercial clients. Our service portfolio includes cybersecurity assessments and advisory, hosted SIEM and EDR/XDR solutions, software assurance, penetration testing, cybersecurity engineering, and compliance audit support. We specialize in serving organizations that operate within some of the world’s most highly sensitive and tightly regulated environments where unwavering security, strict compliance, technical excellence, and operational maturity are non-negotiable requirements. Our proven track record in these domains positions us as the premier trusted partner for organizations where technology reliability and security cannot be compromised.
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