Boutique Australian Cyber Security

We breach it first,
so attackers can't.

C4 Cyber is a specialist security testing firm. We think like real adversaries - penetration testing, red teaming and breach simulation - then translate what we find into clear, implementable steps that harden your business.

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  • OSCP certified
  • AGSVA cleared
  • MITRE ATT&CK · OWASP · PTES
OSCPOffensive Security Certified Professional
4%of Australia's GDP handled by systems we've breached in testing
$1B+annual value processed by systems we've assessed
100%Australian citizens, minimum baseline clearance

Trusted across highly critical environments

  • Australian Federal Government
  • NSW & VIC State Governments
  • Critical Infrastructure
  • Financial Services
  • Insurance
  • Universities
  • Legal Firms
  • Multinationals

What we do

Security services, tailored to your real risk

Every engagement starts with a conversation about what matters most to your business, then simulates the attack paths that actually threaten it.

Cyber Security Assessment

A tailored assessment built around your concerns. We map the attack points you could realistically face and quantify the actual risk across a suite of scenarios.

Penetration Testing

Internal and external testing that simulates real-world adversaries against your web apps, networks and cloud - grounded in MITRE ATT&CK, OWASP and PTES, plus original research on your specific stack.

Breach Simulation

Assume you're already breached. We test how far an attacker moves once inside - stolen credentials, a lost laptop, malware, rogue devices or a compromised B2B partner.

Red Team Assessment

Full-scope adversary emulation using any means necessary - including physical access, badge cloning and social engineering - to reach your most sensitive environments and prove business impact, safely.

OE Platform Monitoring

Continuous monitoring of your cloud and internet-facing infrastructure. When a change is detected, a C4 analyst reviews it - and if it creates exposure, you're notified.

Vulnerability Management

Ad-hoc or scheduled vulnerability scanning with prioritised, practical remediation guidance so the issues attackers are most likely to exploit get fixed first.

Our approach

Recognised frameworks. Original research.

We combine the industry's leading methodologies with hands-on research into the actual technologies you run - which regularly uncovers techniques specific to your environment.

Talk through your scope

MITRE ATT&CK®

A knowledge base of real-world adversary tactics and techniques - from initial access through privilege escalation, lateral movement and impact.

OWASP

The de-facto standard for web application security testing, covering the most prevalent and damaging web vulnerabilities.

PTES

The Penetration Test Execution Standard - a rigorous framework for managing penetration tests and red team engagements end to end.

AI-augmented testing

We use AI in our testing

Frontier AI models are part of how we work. They let us cover more ground, reason about complex attack paths faster, and concentrate our time where human judgement genuinely matters. Every engagement is still scoped, led, validated and reported by a human tester - AI accelerates the work, it does not replace the operator.

Verified

Anthropic Cyber Verification Program (CVP)

C4 Cyber is a member of Anthropic's Cyber Verification Program, an application-based vetting program that grants approved security organisations access to Claude's dual-use cybersecurity capabilities.

Capabilities such as vulnerability exploitation analysis, offensive security tooling and adversary simulation are restricted by default. Anthropic reviews each applicant organisation, what it builds and how it intends to use the access, then lifts those restrictions only for verified teams doing legitimate defensive work.

Acceptance into the program means our use of AI in penetration testing is vetted, scoped to defensive security work, and governed by Anthropic's security, confidentiality and responsible-use requirements.

Case study

Chaining a path to the critical data

A large organisation engaged us after a non-hacking information breach. The remedial plan required a penetration test of the system involved in the leak.

  1. 01 We established with the client that the secure data on Server A was the critical data that had to be protected.
  2. 02 Using open-source intelligence, we discovered additional internet-facing servers and proposed an attacker's path via Server B.
  3. 03 We gained access to Server B over the internet and escalated to administrator.
  4. 04 From there we moved laterally to Server A and demonstrated access to the secure data - exactly as a real adversary would.
  5. 05 Our report delivered meaningful security-architecture advice to harden every step of that path. The client implemented the measures and we validated each one.

About C4 Cyber

Integrity and trust, in the highest-stakes environments

C4 Cyber is a boutique cyber security firm delivering practical, affordable and implementable security solutions. Our people are trusted to work in highly critical environments and for clients requiring special clearances - all C4 Cyber staff are Australian citizens holding a minimum baseline clearance.

Integrity and trust are core values in everything we do. We're passionate about cyber security and thrive on the challenge of an ever-evolving threat landscape.

Get in touch

Ready to find out what an attacker could do?

Tell us what you're worried about and we'll build an assessment plan around it. We'll get back to you within one business day.

Prefer email? contact@c4cyber.com.au