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Offensive security that finds exploitable weaknesses before adversaries do. An offensive security firm of operators who would rather break your systems in a controlled engagement than read about it in the news.
SubZeroSec was founded in 2019 by operators who spent years breaking into the systems other people assumed were secure. The pattern was always the same: the weakness was there long before the breach, waiting to be found. The only question was who found it first.
So we built a firm around a single discipline — offensive security. We intercept vulnerabilities on the path to becoming zero-days through penetration testing, red teaming, threat hunting, OSINT, and attack surface analysis, so that a breach never happens in the first place.
Our mission is simple: see your organization the way an adversary does, and tell you what they would do about it — before they get the chance. That is the meaning behind Before Zero. Beyond Breach.
We earn our findings by compromise, not checklists. Everything we recommend is grounded in how a real attacker would actually break in.
We hold our clients' most sensitive systems in trust. Discretion, tight scoping, and careful handling of evidence are non-negotiable.
A finding nobody can fix is noise. We prioritize by real business impact and write so engineers and executives both know what to do next.
Adversaries evolve, so we do too. We track the threat groups that matter and fold live tradecraft back into every engagement.
+127+ Critical Findings
Critical Findings
Confirmed critical-severity issues proven exploitable across client engagements.
+340+ Assessments Delivered
Assessments Delivered
Penetration tests, red-team operations, and hunts completed to date.
%98% Remediation Rate
Remediation Rate
Share of high and critical findings verified closed at retest.
+15+ Industries Secured
Industries Secured
Regulated and high-target sectors served, from banking to telecoms.
A senior bench of testers, red teamers, and intelligence specialists who have spent careers on the offensive side.
We align our work to the standards and frameworks that set the bar, and hold our own house to the same scrutiny we apply to clients.
Independent accreditation of penetration testing and red-team services to a recognized professional standard.
Hands-on, exploitation-focused certifications held by our operators, earned through practical compromise rather than multiple choice.
International standard for information security management, governing how we handle our own and our clients' data.
Independent attestation of our security, availability, and confidentiality controls over a sustained period.
Qualified Security Assessor capability for testing and validating environments that store or process payment-card data.
UK National Cyber Security Centre scheme for delivering penetration testing to public-sector and critical national infrastructure.
See our full security posture on the Trust & Compliance page.
Book a security assessment and see your organization the way an adversary does.