Offensive security, Attack path validation, and Remediation retest
Find Out What an Intruder Could Actually Do
Meet the specialist behind this practice, Robert Knudsen.
A vulnerability scan tells you what is exposed, a penetration test tells you what an intruder could do with it. Our testers chain the findings the way an attacker would, validate each attack path and retest after you remediate, so the report describes real risk rather than a list of ports.
Preparing a scope? Read the security assessment and penetration test preparation guide before the call.
Scope the engagement
Define the Attack Surface Worth Testing Before Anyone Touches a Keyboard
Tell us which networks, applications, APIs or cloud tenants concern you, how they support the business and when you need the findings. GDF has operated since 1992. Founder Joseph Caruso brings a career in systems engineering and cybersecurity incident response and holds the CISSP, and Robert Knudsen combines the CISSP, CompTIA Security+ and Network+ with eighteen years of forensic casework in federal and state court matters. We plan testing around your operating constraints, your change windows and the questions your board, your customers and your regulators are asking.
Systems and access paths to test
We agree the networks, applications, APIs, cloud tenants and identity controls in scope, including the connections between them that could carry an attack from one system into another.
Findings ranked by business consequence
You receive an executive summary, validated findings with reproduction steps and supporting evidence, and remediation priorities ordered by what each weakness could cost the business.
Evidence discipline from a forensic practice
Testing activity is recorded, every finding is reproduced before it is reported and the supporting artifacts are preserved, so your team, your auditor or your counsel can see what was done and when.
Gather records before an engagement
Gather the Records That Make Your First Scoping Call Count
Choose a guide to organize records, assign owners and prepare questions for the relevant auditor, consultant, counsel or export control specialist.
These guides help you prepare for the discussion with your auditor, assessor, counsel or specialist. They do not replace an audit, assessment, legal opinion or specialist decision, and they do not authorize testing.
Read the overviews without a form. Downloads require your name and email; we email an access link valid for seven days. Organization and phone are optional.
Discuss your assessment scope
Security Assessment and Penetration Testing Preparation
Record proposed scope, owners, safety boundaries and permissions before audit, security assessment or physical or cyber testing.
File: Editable CSV preparation checklist.
OT assessment planning resources
Use the four sector packs, project workbook and shared source records to organize a proposed OT assessment.
File: ZIP: PDFs, XLSX workbook and CSV records.
Browse all preparation packages by subject.
Check each overview for source dates, scope limits and unresolved questions before using a download.
Follow the Attack Paths a Real Intruder Would Use
GDF penetration testing examines how an attacker could enter your environment, escalate privileges, move between systems and reach the data or operations that matter. We test authorized networks, applications, APIs, identity controls and cloud access, then chain the weaknesses we confirm into the attack paths an intruder would actually follow, because a medium severity flaw on its own and the same flaw beside a reused administrator credential are two very different risks.
Experienced GDF testers direct every engagement. They use practical testing tools, open source intelligence and AI assistance to map the approved attack surface and develop test cases, and they validate each potential weakness by hand before it becomes a finding. You receive evidence your team can reproduce, a plain statement of what the finding means for the business and the discipline of a practice whose examiners have testified in federal and state courts.
One Engagement Across Network, Application, Cloud and Identity
A vulnerable application exposes data. A compromised account opens a path into the network. A permissive cloud role turns a foothold into an outage. Attackers do not respect the boundaries between your teams, so we test across them, with the scope built around the systems your business depends on.
External penetration testing examines internet facing systems, exposed services, remote access gateways and the information an outsider can gather about your organization to show how an attacker would approach the perimeter.
Internal testing and assumed breach exercises begin from an agreed foothold, such as a compromised workstation or a standard user account, and examine privilege escalation, movement between systems and the segmentation that is supposed to contain an intruder.
Web application and API testing examines authentication, session handling, authorization, data access, business logic and the connections between applications to find the paths to unintended actions or information.
Cloud and identity testing examines administrative access, role assignments, account privileges and the paths from an ordinary identity to sensitive resources, so your team can remove the excess access that turns a small compromise into a large one.
Source code review examines the security sensitive implementation behind authentication, authorization and data handling and connects what the code says to what the running application does, which gives developers the root cause rather than a symptom.
Red teaming pursues an agreed objective across the defenses in scope and shows what your security team detects, how your controls respond and where the response can improve.
Explore our application penetration testing and source code security review methods, or discuss a combined engagement.
Not sure where the scope should start? Describe the systems your business depends on and a senior tester will propose the boundaries.
Talk Through Scope, Depth and Price Before You Commit
Tell us what you need tested, why and by when. A senior tester will walk you through the approach, the deliverables and the price in a free initial consultation.
Choose the Testing Depth Your Question Requires
Black box testing of exposed systems
We begin with little more than an outside attacker would know and assess the exposed systems and access paths that attacker could discover. This outside view shows what your public environment reveals before credentials or internal documentation are provided, and it is the right starting point when the question is how you look from the internet.
Gray box testing with selected access
Selected accounts, documentation or architecture details let us examine what users at different privilege levels can actually do. This approach gives deeper coverage of internal access, application permissions and the separation of customer data, and it is usually the most efficient way to answer the question most boards ask, which is what happens after a single credential is stolen.
White box testing and source code review
With source access and system context, we examine the code behind authentication, authorization, data handling and business rules and connect the implementation to the running application. Developers receive the specific conditions that create each weakness rather than a symptom to chase, which shortens remediation and makes the retest conclusive.
If you are weighing black box against gray box for an upcoming audit, call (800) 868-8189 and we will recommend the depth that answers your question at the lowest cost.
Human Judgment Directs the Test, AI Accelerates It
AI can organize reconnaissance, correlate observations and develop test cases across the approved targets faster than a person working alone. GDF testers select the tools, direct the testing and validate every result, because the difference between a useful finding and a misleading one is judgment, and judgment is not something we delegate. Nothing enters your report that a tester has not reproduced.
Our documented workflow carries each finding from discovery through validation, reporting and retesting. Your engineers get the reproduction steps; your leadership gets the business impact and the priorities. Read more about AI assisted penetration testing.
Before the scoping call, work through the assessment preparation checklist so authorization, owners and windows are already settled.
Test Detection and Response With a Red Team Exercise
A penetration test identifies and validates exploitable weaknesses. A red team exercise pursues an agreed objective across the defenses in scope and shows what your security team detects, how your controls interrupt the activity and where the response can improve.
We agree targets, operating hours, permitted techniques, escalation contacts and stop conditions before testing begins, and the exercise leaves your defenders a record of the activity they can measure themselves against.
Want your defenders measured against a realistic objective? Describe the objective and the controls in scope and we will plan the exercise with your IT lead.
The GDF process
Nine Steps From First Reconnaissance to Final Report
From the first target profile to the final retest, each step builds the evidence your team needs to understand the exposure and act on it.
Discover the attack surface
Understand the environment the way an attacker would
Profile
We gather public information about the approved targets, including domains, exposed services, employee footprint and technology, to see the environment an outside attacker would discover first.
Verify
We confirm targets, written authorization, testing windows and escalation contacts with your IT lead so the engagement stays inside approved operational boundaries from the first packet.
Initial scanning
We identify the networks, hosts and services in scope to establish coverage and direct the tests that follow.
Enumeration
We review services, accounts, software versions and access details to select tests appropriate to the environment rather than running every tool at every host.
Validate the attack paths
Prove what an intruder could do
Attack plan
We review the proposed attack paths with your IT lead to confirm permitted techniques, operating conditions and stop rules before any exploitation begins.
Exploit
We execute the approved plan, confirm access and privilege findings by hand and preserve the evidence so your team can reproduce every material result.
New networks or higher access found?
Yes: Return to Profile. Confirm any scope change before testing additional targets.
No: Continue to Analysis.
Explain the business impact
Turn findings into decisions
Analysis
We connect each result to the systems, data and operations it affects so every technical weakness carries a clear business consequence.
Review
We walk through the findings with your team and agree remediation priorities so engineering effort goes to the most consequential issues first.
Final report
We deliver the executive summary, the technical evidence and the agreed next steps, and where retesting is in scope we verify the corrections and record their status.
A report that helps you fix the right things first
- Executive summary
- The business exposure and the decisions that deserve leadership attention.
- Validated findings
- Affected systems, reproduction steps and evidence of the demonstrated impact.
- Attack path analysis
- How individual weaknesses combine to reach the agreed objectives.
- Remediation priorities
- Practical fixes ordered by exposure and business consequence.
- Retest results
- Verification of the agreed corrections and a clear record of what remains open.
Tell us whether the report is for your engineers, your CISO, your board, a customer assurance process or an upcoming audit, and we will plan the deliverables around that audience.
Request a Pen Test Scope & QuoteFrequently asked
Penetration Testing Questions Security Leaders Ask Us
Can GDF test our network, applications and cloud access in one engagement?
Yes. We combine external and internal network testing, web application and API testing, cloud and identity testing and source code review in one defined scope, and we follow the paths between those systems, because that is where a real intruder moves.
What is the difference between black box, gray box and white box testing?
Black box testing starts with little more than an outside attacker would know. Gray box testing adds selected accounts or architecture details so we can test what users at different privilege levels could reach. White box testing adds source code and system context so the findings reach the root cause. We help you choose the depth that fits the question you need answered.
How are findings ranked?
By business consequence, not by a scanner severity score alone. Each finding states what we demonstrated, the conditions it depends on, the systems and data it could reach and what it would cost you if an attacker did the same, so your engineers fix the issues that matter first.
How do you use AI in penetration testing?
AI tools assist with reconnaissance, correlation and test case development across the approved targets. GDF testers select the tools, direct the work and validate every finding before it enters the report. Nothing reaches you that a person has not reproduced.
Is a retest included?
Where it is agreed in the scope, yes. After your team remediates, we retest the corrected findings and record their status, so the final report shows what was found, what was fixed and what remains open.
How do we get a scope and price?
Tell us which networks, applications and locations are involved, your deadline and the outcome you need, for example a board report, a customer assurance request or a regulatory deadline. The scoping consultation is free, and we discuss testing depth, access, reporting and retesting so the proposal reflects your priorities.
Incident Response and Forensics When the Test Finds Something Live
Need to test one application, the code behind it, an AI deployment or a plant? Application testing, source code review, AI assisted testing and OT assessments each scope that narrower question.
Put Your Attack Surface in Front of a Senior Tester
Share the systems or application you want tested, the business concern behind the request and your deadline. We will recommend the testing depth, the report your audience needs and the retest that records whether each fix held, and the first consultation is free.
Reviewed by Joseph Caruso, Founder, CEO and CTO, CISSP. Last reviewed .