Security expertise for the problems AI just created.
Zero Day Security is a practitioner-led security and AI-security advisory firm. We help organizations adopt agentic AI without losing control of the risk, and we are honest about what security can and cannot do.
Most organizations are adopting AI faster than they can secure it. The tooling market is loud, the threat landscape is new, and the controls that worked for software and people were not designed for systems that read untrusted content, hold their own access, and act on their own.
We exist to close that gap with judgment, not hype: a clear read of where you stand, a sequenced plan to fix it, and the hands-on work to deliver it. We work across the full security lifecycle, with deep focus on AI and agentic systems.
What we believe
Signal over noise
We do not quote vendor statistics we cannot stand behind, and we will tell you when a problem has no product that solves it. Some of the hardest AI-security gaps are architecture and engineering decisions; pretending a tool makes them disappear helps no one.
Posture is not protection
Discovering and scanning your AI tells you what you have and where it is weak. It does not stop anything at runtime. You cannot protect what you cannot see, so visibility comes first, but visibility on its own is not a control. We build both, in the right order.
Vendor-neutral by default
We are not resellers. When a tool is the right answer we will say so, and when an evaluation is needed we run it against a defensible framework and prove it in a sandbox before anyone signs a contract.
Diagnose for everyone, prescribe for clients
Our free assessment shows any organization what is wrong with its AI posture. The how-to-fix is the engagement. That split is deliberate: you should be able to understand your risk before you ever talk to us.
The standards we work to
Our assessments and reviews are grounded in public, recognised frameworks rather than our own opinions:
Who we work with
Four kinds of organization, with one thing in common, they are adopting AI and need to do it safely:
- Enterprises adopting agentic AI, including banks, financial institutions and credit unions, who need governance, guardrails and board-level assurance.
- AI-native apps, developers and startups breaking into regulated industries, who need security reviews, a retainer, pentests and SOC 2.
- Private equity firms and investors, who need security and AI-strategy due diligence on the deal and a partner after close.
- Law firms, who need fractional security leadership and safe adoption of AI and legal-tech tools.
See where you stand, free.
The fastest way to understand how we think is to run the assessment. Three minutes, no login, board-ready output.