Your Antivirus Is the Malware You Installed Voluntarily

Originally published in full on blog.nicolabaudo.fr — this is the essential version for newsletter subscribers.

Try this thought experiment: name one piece of software on your computer that has unrestricted root access to every file, scans everything you open, monitors every URL you visit, and phones home with the results.

You're thinking of malware. I'm describing your antivirus.

This isn't a rhetorical trick. It's architecture. And once you see it, you can't unsee it.

The Box You Invited In

Antivirus software operates on a premise that is also a privacy nightmare: to protect you from malicious files, it must inspect all files. Every document. Every photo. Every email attachment. Every password manager database. Every encrypted volume mounted during a scan. On Windows it runs as SYSTEM. On macOS it hooks into the kernel. On Linux it demands root.

The GDPR defines personal data as any information relating to an identifiable person. Your AV isn't glancing at metadata — it's deep-inspecting file contents, process memory, network traffic, browser history. That's not "some personal data." That's your entire digital life.

And what does it do with all this? The short answer: everything you wouldn't want.

Avast, through its subsidiary Jumpshot, sold browsing data from roughly 100 million users to over 100 third parties — consulting firms, investment funds, advertising networks, data brokers. Non-aggregated, re-identifiable, with unique per-browser identifiers. The Czech Data Protection Authority confirmed the violation and the €13.9 million fine became final in April 2024.

Avast isn't the exception. Avast is the one that got caught.

The Yogurt Test

There's a deeper pattern here. Every commercial AV vendor asks you to do something no security professional would accept in any other context: grant unrestricted access to an entity you cannot audit, on the promise that it means you no harm.

This isn't a security decision. It's a theological one — you're being asked to have faith. And faith is not a control under ISO 27001.

Consider a yogurt. When you buy one, you flip the container and read the ingredients. Not the recipe — the manufacturer keeps their fermentation process secret. But they disclose what's in the product. You accept that list as truthful not because you trust the manufacturer, but because independent regulatory authorities exist to verify those claims and sanction non-compliance.

That system isn't perfect. Regulatory capture is real. Agencies get underfunded and corrupted. But the principle is sound: independent verification creates a structural incentive for honesty that corporate promises can't replicate.

Closed-source antivirus gives you none of this. You can't flip the container. There's no ingredients list — just a privacy policy written in weasel words by lawyers maximizing legal latitude. There's no regulatory authority auditing what your AV actually collects versus what it claims to collect. The Czech DPA fined Avast €13.9 million — but only after a whistleblower exposed the practice, only after years of data sales, and only for one vendor among dozens.

The GDPR doesn't use the word "trust." It uses "demonstrate" — Article 5(2) puts the burden of proof on the controller. You must show compliance, not merely believe in it. And you cannot demonstrate what you cannot verify.

When Your Protector Becomes Your Accuser

The threat model so far has been extraction — your AV takes data from you. But a system with unrestricted root access and a permanent encrypted connection to remote servers is capable of something worse: injection.

A few strategically-named files in the right directories. A modified browser history entry pointing to something you never visited. A "detected threat" that was never on your machine — planted by the software that then "discovers" it. Suddenly you're not the victim. You're the suspect.

When Julian Assange was arrested at the Ecuadorian embassy in 2019, WikiLeaks editor-in-chief Kristinn Hrafnsson stated that Assange had scrubbed his computers before the arrest — precisely because he anticipated that any data subsequently found would have been planted. "If anything surfaces, I can assure you it would've been planted." Ecuadorian authorities, at the U.S. government's request, took possession of all his equipment. Chain of custody: broken. Whatever was "found" afterward: unverifiable.

At this point you might think: this is disturbing, but it doesn't apply to me. I'm not Julian Assange. I keep my head down. I'm not on anyone's radar.

The COVID era proved otherwise — at unprecedented scale.

Between 2020 and 2022, hundreds of thousands of ordinary people — doctors, nurses, teachers, parents, small business owners — had their accounts suspended, their posts labeled "misinformation," their professional reputations destroyed. Not because they were spies or dissidents. Because they questioned vaccine mandates. Because they shared early-treatment data. Because they posted a link to a study that contradicted the institutional narrative.

This wasn't fringe content. Dr. Luc Montagnier, Nobel laureate for co-discovering HIV, was deplatformed for questioning vaccine safety. If a Nobel Prize winner isn't safe from the machinery of censorship, you aren't either.

And the consequences were not abstract. People lost jobs. Parents lost custody battles because their social media history was submitted as evidence of unfitness. Doctors lost their licenses for prescribing treatments that later proved effective. The digital trail became a weapon — not against criminals, but against anyone who deviated from the approved narrative.

Today's heterodoxy is tomorrow's orthodoxy: the CDC has now revised its position on the vaccine-autism question, acknowledging that the claim "vaccines do not cause autism" is not evidence-based. Views that got people deplatformed in 2021 are now official government positions. But the people whose lives were destroyed in the interim don't get a refund on their reputations.

Your AV is part of this infrastructure. It has root access to the files that could discredit you. It operates on an update channel that could be compromised. And the threshold for becoming a target, as the COVID era proved, can be as low as sharing a study the algorithm didn't like.

What Actually Works

If cloud-connected AV is both a privacy violation and a security liability, what replaces it? Not another product. Architectural discipline:

• Minimal attack surface. Run only what you need. Every installed package is a liability. You cannot exploit what isn't there — that's Article 25 (data protection by design) made operational.
• Compartmentalization. If your browser gets owned, it shouldn't touch your documents. Separate Unix users, restricted filesystem views — the compromise of one component stays contained.
• Read-only wherever possible. An immutable base system eliminates malware persistence. Data partitions with noexec prevent downloaded files from becoming running processes.
• Network-level filtering. Block malicious infrastructure at the router or DNS resolver, not on the endpoint. A compromised router can't read your files; a compromised AV can.
• Application firewalls. On OpenBSD, PF restricts outbound connections by user ID. The browser user reaches the internet; the document-processing user doesn't. No vendor can push an update that silently changes your rules.

None of this requires closed-source kernel modules from a company whose business model depends on harvesting your data. It requires understanding your system — the very skill that two decades of "it just works" computing have systematically extracted from us.

The Bottom Line

Every commercial antivirus is, by fundamental architecture, anti-privacy by design. It scans everything, uploads everything, and monetizes everything — or builds the infrastructure that makes future monetization inevitable.

If you're processing personal data under GDPR with a cloud-connected AV across your fleet, you're gambling with fines up to 4% of global annual turnover. The Czech DPA has already set the precedent. More decisions are coming.

The question isn't whether your antivirus violates GDPR. The question is who gets fined first — you, or your vendor.

This is the first in a series of articles building the philosophical infrastructure behind dropQbsd — compartmentalization without virtualization on BSD. The full version, with detailed data flow analysis, regulatory references, and case law, is on blog.nicolabaudo.fr.

Was this forwarded to you? Subscribe here. No tracking, no algorithm — just philosophical analysis of digital tools, every Sunday.