We simulate the attacker who already got in. Our internal network penetration tests show exactly how an adversary inside your perimeter would escalate privileges, move laterally, and reach the data that matters — paired with a fix path your engineers can ship.
What is Internal Network Penetration Testing?
Internal network penetration testing simulates an attacker who has already breached your perimeter — through a phished employee, a compromised vendor, or a misconfigured service exposed to the internet. The test answers one question: from inside your network, how far could an adversary actually get?
Unlike automated scanners, which match systems against a list of known vulnerabilities, an internal pentest is a live simulation. Senior testers chain misconfigurations, abuse legitimate functionality, escalate privileges across systems, and pivot toward your sensitive data — using the same techniques real attackers use.
Why your environment needs this test
Most organizations spend the bulk of their security budget on perimeter defenses — firewalls, EDR, email filtering. Those defenses keep attackers out. They do not tell you what happens when one gets in anyway.
The data is uncomfortable: industry-wide, the median time between an attacker reaching your internal network and reaching your crown-jewels data is measured in hours, not days. Internal segmentation is usually thinner than expected. Service accounts hold more privilege than they need. A flat network with one weak credential collapses faster than most security teams realize.
An internal pentest gives you ground-truth on three questions:
- What’s the actual blast radius of a single compromised user or host?
- Which controls hold up under hands-on attack, and which are theatrical?
- What needs to be fixed first — based on real exploitability, not CVSS score?
CyberBullet’s methodology
Every internal pentest follows the same disciplined arc — so nothing slips through, and you know exactly what to expect.
1. Scoping & Rules of Engagement
We don’t start until the scope, success criteria, and rules of engagement are written down and signed by both sides. This includes in-scope systems, explicit out-of-bounds targets, testing windows, emergency-stop procedures, and the starting position for the test (unauthenticated insider, stolen credentials, or authenticated low-privilege user).
2. Reconnaissance & Asset Discovery
Before exploiting anything, we map your real attack surface — every service, host, trust boundary, and authentication system. This step alone often surfaces shadow IT and forgotten infrastructure clients didn’t know was on the network.
3. Vulnerability Identification
We combine automated scanning (for breadth) with manual analysis (for depth) to identify every weakness worth investigating — outdated services, misconfigurations, weak authentication, exposed credentials, and architectural flaws that scanners miss entirely.
4. Active Exploitation
This is where the engagement diverges sharply from a scan. We chain findings into real exploit paths: from initial foothold to local privilege escalation to lateral movement to domain compromise. Every step is documented with proof.
5. Lateral Movement & Privilege Escalation
We don’t stop at one host. We pivot through the network the way an attacker would, escalating privileges along the way, mapping which systems your existing user could realistically reach and what they could do once there.
6. Reporting & Remediation Guidance
The report is the deliverable — and most reports we see from other firms are a list of CVSS scores with no operational guidance. Ours pair every finding with: an executive summary anyone can read, technical detail with screenshots and command captures, a concrete remediation path your engineers can ship, and a re-test recommendation so you know when you’re actually safe.
Frameworks we map findings to
Our reports map every finding to the relevant control families so you can hand them directly to auditors and compliance teams:
- CIS Critical Security Controls (v8)
- NIST Cybersecurity Framework (CSF 2.0)
- PCI DSS (4.0) for cardholder-data environments
- HIPAA Security Rule for healthcare environments
- SOC 2 for service organizations
- NAIC Insurance Data Security Model Law for insurance carriers
- MITRE ATT&CK technique mapping for SOC tuning
Who this is for
- Mid-market organizations with critical data on internal systems and a formal compliance obligation (HIPAA, PCI, NAIC, SOC 2)
- Companies preparing for a customer security review — vendor risk questionnaires increasingly ask “when did you last conduct a manual internal pentest?”
- Organizations recovering from an incident — post-incident testing validates that the root-cause issues are actually closed
- Security teams who already do scanning and want to know what scanners miss — and what an attacker would actually do with what’s on their network
Our methodology
Every engagement runs through the same six phases. Manual validation isn't a finishing step — it's the product.
Scope & Authorize
We define the engagement boundary precisely before testing starts — in-scope assets, out-of-bounds targets, testing windows, and emergency-stop procedures.
- Written authorization letters exchanged before any packet leaves our infrastructure
- Signal / Slack channel established for real-time findings during the engagement
- Explicit rules of engagement reviewed with legal, IT, and business stakeholders
Passive Reconnaissance
Before a single packet touches your infrastructure, we map your external footprint using public sources only — DNS, CT logs, code repos, internet-wide scan data.
- Typically discovers 15-30% more attack surface than the client originally provided
- Certificate transparency, BGP, and GitHub exposure reporting
- OSINT profile for social engineering vectors if in scope
Active Discovery
We enumerate live services across in-scope assets — ports, software versions, auth mechanisms, and protocol configurations — correlated against current vuln data.
- Hand-tuned scanning profiles — not the default Nessus run
- Protocol-level inspection for TLS, SSH, SMB, Kerberos, LDAP
- Service fingerprinting to ground truth before any exploitation
Manual Validation
Every potential issue is validated by hand before it makes the report. No CVE-dumping. No false positives. This is what separates the engagement from a scan.
- Manual exploitation attempts for any finding of High severity or above
- Business-logic testing on top of the technical layer
- Chained vulnerabilities analyzed as a single attack path
Exploitation & Impact
For confirmed vulnerabilities with attacker value, we attempt exploitation to prove impact — not just that a CVE applies, but what it gets you.
- Proof-of-exploit captured for every confirmed critical finding
- Pivot paths mapped to the actual crown-jewel data
- Interim notification inside 24 hours for anything critical
Report & Remediate
Every finding is paired with severity rated on real exploitability, reproducible proof-of-exploit, and remediation guidance your team can ship this sprint.
- Executive summary and technical deep-dive in a single report
- Findings mapped to CIS, NIST CSF, and relevant compliance families
- Retest included — we confirm the fix before we close the finding
What you walk away with
Frameworks we map to
Findings ship mapped to the control families your regulators and auditors actually check. Governance clients use these crosswalks directly in their program documentation.
- CIS Controls v8
- NIST CSF 2.0 / 800-53
- PCI DSS 4.0
- HIPAA Security Rule
- SOC 2 Type II
- OWASP ASVS
Questions we get asked
How is internal network penetration testing different from a vulnerability scan?
A vulnerability scan finds known issues against a database of CVEs — it tells you what's listed as broken. An internal pentest answers the question that actually matters: if an attacker were inside your network, could they reach the crown jewels? We chain real exploits, abuse misconfigurations, escalate privileges, and pivot the way an adversary would. Scanners can't do that.
Will the test disrupt our production environment?
Properly planned, no. We invest meaningful scoping time up front to identify production-critical systems, agree on testing windows, and define the rules of engagement. Communication channels stay open throughout — we can pause, adjust, or skip anything that risks operational impact. Disruption only happens when planning is rushed.
How long does an internal network pentest take?
A focused engagement on a small-to-mid environment (50-200 hosts) typically runs 1-2 weeks of active testing plus a week of reporting. Larger environments (500+ hosts or multi-site) run 2-4 weeks. Every engagement is sized to your actual environment — no minimum-billable-hour padding.
What's required from our team?
Less than you'd think. We need network access (VPN or on-site), a contact for emergency-stop coordination, and a kickoff call to walk through the scope. We don't need credentials by default — the engagement type determines whether we operate as an unauthenticated insider, a stolen-credentials attacker, or an authenticated user. We'll recommend the right starting position during scoping.
Do you re-test after we remediate findings?
Yes — every engagement includes a 90-day re-test option for any findings we identified. This validates that fixes actually closed the attack path (not just that the CVE got patched) and gives you clean evidence for auditors, boards, and customers asking 'did you actually fix it?'