Top 10 Best Internal Penetration Testing Services in 2025

Internal penetration testing is a crucial part of a complete cybersecurity strategy. While external testing focuses on what an attacker can see from the outside, an internal penetration test simulates a breach from within the network, mimicking a malicious insider or an attacker who has already gained a foothold.

This type of testing is essential for identifying weaknesses in network segmentation, misconfigured systems, and a lack of proper privilege controls vulnerabilities that could lead to a catastrophic data breach.

In 2025, with hybrid workforces and complex on-premises and cloud environments, a robust internal test is more vital than ever.

Why We Chose Internal Penetration Testing

The primary goal of an internal penetration test is to answer a critical question: “Once an attacker is inside, what can they do?” Traditional perimeter defenses like firewalls and anti-malware software are often bypassed by sophisticated attacks.

The top companies in this field go beyond simple automated scanning to perform manual, hands-on testing that uncovers logical flaws, misconfigurations, and privilege escalation vulnerabilities that could lead to full network compromise.

This is a critical security exercise that validates your defenses against one of the most common and dangerous attack scenarios.

How We Chose Best Internal Penetration Testing Services

Our selection of the top 10 internal penetration testing companies is based on three core criteria:

Experience & Expertise (E-E): We looked for companies with highly certified and respected security professionals, a proven track record of finding complex vulnerabilities, and deep knowledge of modern internal attack techniques, including Active Directory exploitation and cloud misconfigurations.

Authoritativeness & Trustworthiness (A-T): We considered their reputation in the industry, their contributions to security research, and the trust they have earned from enterprise clients and regulatory bodies.

Feature-Richness: We assessed their services for key features such as a blend of manual and automated testing, clear and actionable reporting, and the ability to conduct post-exploitation activities to demonstrate real-world impact.

Comparison Of Key Features (2025)

Company	Human-Led Testing	Platform/PTaaS Model	Adversary Emulation	Compliance Expertise
Rapid7	✅ Yes	✅ Yes	✅ Yes	✅ Yes
Coalfire	✅ Yes	❌ No	✅ Yes	✅ Yes
Synack	✅ Yes	✅ Yes	✅ Yes	✅ Yes
CrowdStrike	✅ Yes	✅ Yes	✅ Yes	❌ No
Secureworks	✅ Yes	❌ No	✅ Yes	✅ Yes
Offensive Security	✅ Yes	❌ No	✅ Yes	❌ No
Packetlabs	✅ Yes	✅ Yes	✅ Yes	✅ Yes
Cobalt	✅ Yes	✅ Yes	✅ Yes	✅ Yes
UnderDefense	✅ Yes	✅ Yes	❌ No	✅ Yes
Bishop Fox	✅ Yes	✅ Yes	✅ Yes	✅ Yes

1. Rapid7

Rapid7 is a leader in internal penetration testing, leveraging its extensive threat intelligence and a team of elite hackers.

Its services go beyond a checklist, using a threat-informed approach that simulates real-world adversary tactics.

The company’s Vector Command Advanced platform combines continuous red teaming with internal network and segmentation testing, helping organizations validate the effectiveness of their internal controls and meet regulatory requirements like PCI and NIST.

Why You Want to Buy It:

Rapid7’s blend of human expertise and its advanced platform provides a continuous, unified view of your internal attack surface.

This helps you identify and prioritize remediation efforts, ensuring your internal defenses can withstand sophisticated attacks and confidently support audit workflows.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Expert-led team with deep knowledge of lateral movement.
Platform/PTaaS	✅ Yes	Vector Command Advanced offers continuous validation.
Adversary Emulation	✅ Yes	Simulates modern adversary TTPs.
Compliance Expertise	✅ Yes	PCI, ISO, NIST, and other frameworks.

✅ Best For: Companies that need a comprehensive, platform-driven approach to internal testing, with a focus on continuous red teaming and compliance validation.

Try Rapid7 here → Rapid7 Official Website

2. Coalfire

Coalfire is a cybersecurity services firm with a strong reputation for its compliance-driven approach to security.

Its internal penetration testing services are meticulously aligned with major security frameworks such as FedRAMP, PCI, and ISO.

The company’s team performs in-depth assessments by simulating the actions of a compromised insider, uncovering vulnerabilities in internal networks and business applications that could lead to a breach.

Why You Want to Buy It:

Coalfire’s expertise in both offensive security and compliance ensures that your internal test will not only be technically sound but will also produce the necessary documentation to satisfy regulatory requirements.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Experienced team of security consultants.
Platform/PTaaS	❌ No	Focus is on traditional, project-based engagements.
Adversary Emulation	✅ Yes	Includes adversary emulation and red teaming services.
Compliance Expertise	✅ Yes	Deep expertise in FedRAMP, PCI, and more.

✅ Best For: Regulated businesses that need to ensure their internal networks and controls meet strict industry standards for compliance and auditing.

Try Coalfire here → Coalfire Official Website

3. Synack

Synack has revolutionized penetration testing with its Penetration Testing as a Service (PTaaS) platform, powered by a curated community of over 1,500 ethical hackers.

For internal testing, Synack’s approach allows for a flexible, on-demand engagement that can leverage a diverse pool of talent to find vulnerabilities faster.

The platform provides real-time visibility into findings, making it easy to track progress and collaborate with testers and developers.

Why You Want to Buy It:

Synack’s model offers speed and scalability unmatched by traditional firms.

The ability to engage multiple skilled researchers on a single internal test can uncover a broader range of vulnerabilities, providing a more comprehensive and efficient assessment.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Global community of vetted ethical hackers.
Platform/PTaaS	✅ Yes	On-demand PTaaS platform with continuous testing.
Adversary Emulation	✅ Yes	The Synack Red Team can perform goal-based emulation.
Compliance Expertise	✅ Yes	Services can be tailored to meet compliance needs.

✅ Best For: Organizations with agile development cycles that need on-demand, continuous internal testing with the flexibility and scale of a crowdsourced model.

Try Synack here → Synack Official Website

4. CrowdStrike

CrowdStrike, a leader in endpoint security, provides expert-led internal penetration testing that focuses on adversary emulation.

The services are backed by CrowdStrike’s unparalleled threat intelligence, ensuring that tests simulate the most recent and relevant attack tactics.

Their team goes beyond a vulnerability scan, focusing on hands-on-keyboard techniques to validate the effectiveness of an organization’s internal controls and detection capabilities.

Why You Want to Buy It:

CrowdStrike’s deep understanding of adversary behavior, derived from its Falcon platform, allows its testers to replicate the most current and dangerous attack techniques.

This provides a truly realistic and valuable assessment of an organization’s internal defenses.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Elite team with extensive red teaming and incident response experience.
Platform/PTaaS	✅ Yes	Findings are managed within the Falcon platform.
Adversary Emulation	✅ Yes	Services are built around real-world adversary TTPs.
Compliance Expertise	❌ No	Focus is on adversarial emulation, not compliance.

✅ Best For: Organizations that want a penetration test from a company with unrivaled threat intelligence and a focus on simulating modern, targeted attacks.

Try CrowdStrike here → CrowdStrike Official Website

5. Secureworks

Secureworks provides threat intelligence-driven internal penetration testing services. Its Counter Threat Unit™ (CTU) research team provides testers with the latest insights into active threats and attack methods.

This ensures that every test is a realistic, up-to-date simulation of an attack.

The team’s expertise allows them to move beyond automated scans to find complex vulnerabilities in internal networks, cloud environments, and physical and social engineering vectors.

Why You Want to Buy It:

Secureworks’s unique blend of expert-led testing and real-time threat intelligence provides an assessment that is truly representative of the risks facing your organization.

This is a critical advantage for staying ahead of new and emerging threats.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Team of highly certified offensive security consultants.
Platform/PTaaS	❌ No	Traditional project-based engagements.
Adversary Emulation	✅ Yes	Services are driven by CTU threat intelligence.
Compliance Expertise	✅ Yes	Services can be tailored for PCI, FFIEC, and HIPAA.

✅ Best For: Companies that need a penetration test that is based on the most current and relevant threat intelligence, simulating the actions of real-world attackers.

Try Secureworks here → Secureworks Official Website

6. Offensive Security

Offensive Security is renowned for its world-class ethical hacking training and certifications (OSCP, OSEP).

Its professional services team applies the same rigorous, hacker-minded methodology to client engagements.

Their internal tests are deep, hands-on, and focused on finding the most creative and non-obvious vulnerabilities, from misconfigurations in Active Directory to lateral movement flaws.

Why You Want to Buy It:

The caliber of Offensive Security’s testers is arguably the highest in the industry.

Their engagements are not about checking boxes; they are about proving a security posture through creative, persistent hacking. This provides an unmatched level of assurance and discovery.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	A team of highly certified and skilled hackers.
Platform/PTaaS	❌ No	Focus is on traditional, deep-dive engagements.
Adversary Emulation	✅ Yes	Uses advanced post-exploitation techniques.
Compliance Expertise	❌ No	Focus is on technical security, not compliance.

✅ Best For: Organizations that need a highly technical, deep-dive internal penetration test from a firm whose brand is synonymous with elite ethical hacking skills.

Try Offensive Security here → Offensive Security Official Website

7. Packetlabs

Packetlabs is a CREST and SOC 2-accredited North American penetration testing company known for its impact-first findings.

Its team of OSCP-certified experts goes beyond industry standards to uncover what others miss, with a particular focus on demonstrating the business impact of a vulnerability.

Their internal penetration tests are thorough and include assessments of on-premises, cloud, and hybrid environments, providing a prioritized, actionable remediation plan.

Why You Want to Buy It:

Packetlabs prides itself on delivering authentic, high-impact findings that have eluded other testers.

Their commitment to using only certified staff and providing a clear, actionable plan makes them a trusted partner for strengthening your internal defenses.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	100% OSCP-certified staff.
Platform/PTaaS	✅ Yes	The Packetlabs Portal provides real-time findings.
Adversary Emulation	✅ Yes	Offers objective-based and assumed breach testing.
Compliance Expertise	✅ Yes	Services can be tailored to meet compliance needs.

✅ Best For: Companies that want a highly skilled and credentialed team to deliver a technically sound internal test with zero false positives and a clear focus on business risk.

Try Packetlabs here → Packetlabs Official Website

8. Cobalt

Cobalt is a leader in Penetration Testing as a Service (PTaaS), offering a platform that combines the expertise of a crowdsourced community with an intuitive workflow.

For internal testing, Cobalt’s platform streamlines the entire engagement, from scoping to remediation.

The model allows for faster test initiation and real-time collaboration between the client and the testers, resulting in quicker remediation of vulnerabilities.

Why You Want to Buy It:

Cobalt’s platform-driven approach simplifies pentesting, making it a seamless part of the development lifecycle.

This allows you to scale security testing, accelerate risk mitigation, and match the pace of modern development.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Curated community of security researchers.
Platform/PTaaS	✅ Yes	PtaaS platform with real-time collaboration.
Adversary Emulation	✅ Yes	Offers objective-based internal tests.
Compliance Expertise	✅ Yes	Supports compliance and audit workflows.

✅ Best For: Agile teams and DevSecOps organizations that need fast, flexible, and continuous internal security testing without the administrative overhead of a traditional engagement.

Try Cobalt here → Cobalt Official Website

9. UnderDefense

UnderDefense is a global cybersecurity firm that provides managed security services and expert-led penetration testing.

Its internal penetration tests are distinguished by a human-led approach that goes beyond scanners to provide clear, actionable reports and remediation guidance.

The company’s expertise spans a range of environments, including cloud and on-premises, ensuring a thorough assessment of your internal attack surface.

Why You Want to Buy It:

UnderDefense’s commitment to human-led testing and clear communication ensures that you receive a high-quality assessment that is easy to understand and act on.

Their services are designed to help you close security gaps and improve your overall posture.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	Team of highly experienced pentesters.
Platform/PTaaS	✅ Yes	A platform for managing findings and remediation.
Adversary Emulation	❌ No	Focus is on traditional pentesting, not red teaming.
Compliance Expertise	✅ Yes	Services can be tailored to meet compliance needs.

✅ Best For: Companies of all sizes that want a hands-on, expert-led internal penetration test that provides clear, actionable findings and remediation guidance.

Try UnderDefense here → UnderDefense Official Website

10. Bishop Fox

Bishop Fox is a pure-play offensive security firm renowned for its elite team of hackers, known as the “Fox.”

The company specializes in internal penetration testing, with a methodology designed to simulate a compromised host or malicious insider.

Their assessments are time-boxed and objective-based, focusing on uncovering vulnerabilities that lead to privilege escalation and lateral movement.

The company also offers Continuous Attack Surface Testing (CAST), a hybrid PTaaS model.

Why You Want to Buy It:

Bishop Fox’s reputation for technical excellence is unmatched.

Their testers are not only technically proficient but also creative, using innovative methods to breach defenses and demonstrate real-world impact.

This provides a deep and thorough assessment that few other firms can replicate.

Feature	Yes/No	Specification
Human-Led Testing	✅ Yes	The elite “Fox” team of security professionals.
Platform/PTaaS	✅ Yes	Hybrid PTaaS model for continuous testing.
Adversary Emulation	✅ Yes	Specializes in red teaming and adversarial emulation.
Compliance Expertise	✅ Yes	Services can be tailored to meet compliance requirements.

✅ Best For: Companies that want a top-tier, white-glove internal security assessment from one of the most respected offensive security firms in the world.

Try Bishop Fox here → Bishop Fox Official Website

Conclusion

In 2025, internal penetration testing is a non-negotiable security practice.

The best companies in this field offer more than a simple vulnerability scan; they provide a realistic, hands-on simulation of a breach to identify critical weaknesses that automated tools miss.

For organizations that need a comprehensive, platform-driven approach, companies like Rapid7, Synack, and Cobalt are excellent choices.

For highly regulated industries, Coalfire and Secureworks provide the compliance expertise needed to satisfy audit requirements.

And for a deep, technical security assessment from an elite team, you can’t go wrong with Offensive Security or Bishop Fox.

By investing in a high-quality internal penetration test, you can proactively harden your defenses and significantly reduce the risk of a catastrophic data breach.