Penetration Testing for Defense

The defence sector has the most stringent cybersecurity requirements of any industry, reflecting the national security implications of defence system compromises. Defence contractors, weapons system manufacturers, military technology providers, and the broader Defence Industrial Base (DIB) must protect classified information, controlled unclassified information (CUI), and critical military capabilities from sophisticated nation-state adversaries.

Penetration testing in the defence sector requires testers with appropriate security clearances and experience with military-grade systems, embedded systems, tactical communications, and classified networks. The US CMMC framework is transforming how defence contractors approach cybersecurity, requiring demonstrated maturity levels for contract eligibility. UK defence pen testing often follows the Defence Cyber Protection Partnership (DCPP) requirements and may require CHECK or CREST certification.

Defence pen testing must cover traditional IT systems, operational technology, weapons platforms, and the increasingly connected battlefield ecosystem while maintaining strict operational security throughout the engagement.

16 providers
Aristi logo

Aristi

CHECK and CREST-accredited Birmingham-based cyber security consultancy with over 15 years of experience delivering penetration testing, red teaming, and OT security assessments for government and private sector clients.

Birmingham, United KingdomContact for pricing
Web ApplicationNetworkMobile AppCloud+7
CRESTCHECKISO 27001Cyber Essentials+2
Verified Feb 2026
CrowdStrike logo

CrowdStrike

Global cybersecurity leader leveraging world-class threat intelligence from the Falcon platform to deliver intelligence-led penetration testing and red teaming.

Austin, Texas, United StatesContact for pricing
Red TeamingNetworkWeb ApplicationCloud+4
SOC 2ISO 27001
Verified Feb 2026
Cyberis logo

Cyberis

CREST and CHECK-accredited UK penetration testing consultancy with CBEST approval, specialising in infrastructure, application, and simulated attack assessments across the public and private sectors.

Worcester, United KingdomContact for pricing
Web ApplicationNetworkMobile AppCloud+4
CRESTCHECKCBESTSTAR+4
Verified Feb 2026
HackerOne logo

HackerOne

World's largest ethical hacker platform with over one million researchers, offering bug bounties and structured penetration testing to the US DoD and Fortune 500.

San Francisco, California, United StatesContact for pricing
Web ApplicationAPIMobile AppNetwork+2
SOC 2ISO 27001FedRAMP 3PAO
Verified Feb 2026
JUMPSEC logo

JUMPSEC

Full-service London-based cybersecurity consultancy with CREST, CHECK, and NCSC accreditations delivering offensive testing, managed detection, and strategic advisory services.

London, United KingdomContact for pricing
Web ApplicationNetworkCloudAPI+5
CRESTCHECKISO 27001Cyber Essentials+2
Verified Feb 2026
Mandiant logo

Mandiant

World-renowned cybersecurity firm now part of Google Cloud, delivering threat intelligence-led penetration testing and red teaming informed by front-line incident response experience.

Reston, Virginia, United StatesContact for pricing
Red TeamingPurple TeamingNetworkWeb Application+5
SOC 2ISO 27001FedRAMP 3PAO
Verified Feb 2026
MDSec logo

MDSec

Elite UK offensive security consultancy specialising in CBEST/STAR/TIBER red teaming, advanced adversary simulation, and CREST-accredited penetration testing for FTSE 100 clients.

Southam, United KingdomContact for pricing
Web ApplicationNetworkCloudRed Teaming+6
CRESTCHECKCBESTSTAR+3
Verified Feb 2026
Best UK ProviderBest for EnterpriseResearch Leaders
NCC Group logo

NCC Group

Global cybersecurity consultancy with CREST, CHECK, and CBEST accreditation, renowned for deep technical research and comprehensive penetration testing services.

Manchester, United KingdomContact for pricing
Web ApplicationNetworkMobile AppIoT+12
CRESTCHECKCBESTISO 27001+5
Verified Feb 2026
Nettitude logo

Nettitude

CREST, CHECK, and CBEST accredited UK consultancy within Lloyd's Register, delivering premium penetration testing for government and critical infrastructure.

London, United KingdomContact for pricing
Web ApplicationNetworkMobile AppIoT+9
CRESTCHECKCBESTISO 27001+1
Verified Feb 2026
Offensive Security logo

Offensive Security

Creators of OSCP, Kali Linux, and Exploit-DB, offering elite penetration testing services from the team that trains the world's ethical hackers.

New York, New York, United StatesContact for pricing
Web ApplicationNetworkRed TeamingSocial Engineering+4
OSCP Employer
Verified Feb 2026
Praetorian logo

Praetorian

Offensive security firm founded by former DoD professionals, offering elite penetration testing and the Chariot continuous attack surface management platform.

Austin, Texas, United StatesContact for pricing
Web ApplicationNetworkCloudIoT+6
SOC 2
Verified Feb 2026
PwC Cyber Security logo

PwC Cyber Security

Global Big Four professional services firm delivering CREST, CHECK, and CBEST-accredited penetration testing and red teaming services from London, serving the UK's largest enterprises and regulated organisations.

London, United KingdomContact for pricing
Web ApplicationNetworkIoTCloud+8
CRESTCHECKCBESTSTAR+2
Verified Feb 2026
Salus Cyber logo

Salus Cyber

Award-winning Cheltenham-based cybersecurity consultancy with NCSC CHECK Green Light status and CREST approval, specialising in defence, government, and critical national infrastructure security.

Cheltenham, United KingdomContact for pricing
Web ApplicationNetworkCloudAPI+5
CRESTCHECKISO 27001Cyber Essentials+2
Verified Feb 2026
SpecterOps logo

SpecterOps

Adversary-focused security firm created by former DoD red team operators. Creators of BloodHound. CREST-accredited for penetration testing, red teaming, and purple team assessments.

Alexandria, Virginia, United StatesContact for pricing
NetworkRed TeamingPurple TeamingSocial Engineering+3
CREST
Verified Mar 2026
Synack logo

Synack

FedRAMP-authorized crowdsourced penetration testing platform combining vetted elite hackers with AI-powered Hydra technology for continuous security testing.

Redwood City, California, United StatesContact for pricing
Web ApplicationNetworkAPIMobile App+3
FedRAMP 3PAOSOC 2
Verified Feb 2026
TrustedSec logo

TrustedSec

Elite offensive security firm founded by a former NSA operator, delivering CREST-accredited penetration testing, red teaming, and adversary simulation to Fortune 500 and government clients.

Fairlawn, Ohio, United StatesContact for pricing
Web ApplicationNetworkCloudAPI+7
CRESTPCI QSA
Verified Mar 2026

Defense Pen Testing FAQs

What clearances are needed for defence pen testing?+

Clearance requirements depend on the classification level of systems being tested. Common requirements include SC and DV clearance (UK), Secret and Top Secret clearance (US), and equivalent national clearances in other countries.

What is CMMC and how does it affect pen testing?+

CMMC requires defence contractors to demonstrate cybersecurity maturity at specified levels. Pen testing validates security controls, supports CMMC assessment preparation, and helps maintain certification once achieved.

Can classified systems be pen tested?+

Yes, classified systems can and should be pen tested, but testing requires cleared personnel, approved facilities, and strict operational security procedures. Specialised providers offer classified system testing services.