ISO 27001 Penetration Testing Providers

ISO/IEC 27001 Information Security Management · Global

ISO 27001 is the international standard for information security management systems (ISMS). It provides a systematic framework for managing sensitive company information and ensuring its confidentiality, integrity, and availability. Annex A control A.18.2.1 specifically requires independent review of information security, which includes penetration testing as a key validation activity.

Organisations seeking or maintaining ISO 27001 certification typically need annual penetration testing covering network infrastructure, web applications, and any systems processing sensitive data. The 2022 revision of the standard introduced new controls around threat intelligence and cloud security that further reinforce the need for regular security testing.

Penetration testing helps organisations demonstrate compliance with ISO 27001 by providing evidence of proactive security assessment and vulnerability management. Testing should cover the scope of the ISMS and be performed by qualified, independent testers.

26 providers
Top UK ProviderElite TestersResearch-Driven
SECFORCE logo

SECFORCE

Leading UK offensive security consultancy based in Canary Wharf, delivering CREST-accredited penetration testing and adversary simulation to organisations with the most demanding security requirements.

95
Score
LOCLondon, United Kingdom
Web ApplicationNetworkMobile App+9
CRESTISO 27001Cyber Essentials
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.

75
Score
LOCManchester, United Kingdom
Web ApplicationNetworkMobile App+13
CRESTCHECKCBEST+6
Nettitude logo

Nettitude

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

64
Score
LOCLondon, United Kingdom
Web ApplicationNetworkMobile App+10
CRESTCHECKCBEST+2
Best for Mid-MarketBest for Financial Services
NetSPI logo

NetSPI

Leading penetration testing firm with the Resolve platform for continuous attack surface management, trusted by nine of the top ten US banks.

60
Score
LOCMinneapolis, Minnesota, United States
Web ApplicationNetworkCloud+8
SOC 2ISO 27001CREST
Trustwave logo

Trustwave

Global managed security provider with the elite SpiderLabs penetration testing team and deep PCI DSS compliance expertise.

57
Score
LOCChicago, Illinois, United States
Web ApplicationNetworkMobile App+7
PCI QSAISO 27001SOC 2+1
Bridewell logo

Bridewell

Fast-growing CREST and CHECK-accredited UK cybersecurity consultancy with deep expertise in critical national infrastructure sectors.

56
Score
LOCBristol, United Kingdom
Web ApplicationNetworkCloud+7
CRESTCHECKISO 27001+1
Pentest People logo

Pentest People

CREST and CHECK-accredited UK penetration testing firm with an innovative SecurePortal platform and transparent pricing for mid-market organizations.

55
Score
LOCLeeds, United Kingdom
Web ApplicationNetworkMobile App+7
CRESTCHECKCyber Essentials Plus+1
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.

53
Score
LOCReston, Virginia, United States
Red TeamingPurple TeamingNetwork+6
SOC 2ISO 27001FedRAMP 3PAO
Best OverallElite TestersResearch Pioneers
Bishop Fox logo

Bishop Fox

Premier US-based offensive security firm known for elite penetration testers, cutting-edge research, and the Cosmos continuous attack surface management platform.

50
Score
LOCTempe, Arizona, United States
Web ApplicationNetworkMobile App+8
SOC 2OSCP Employer
Rapid7 logo

Rapid7

Creators of Metasploit offering enterprise penetration testing integrated with their comprehensive vulnerability management and security operations platform.

50
Score
LOCBoston, Massachusetts, United States
Web ApplicationNetworkMobile App+7
SOC 2ISO 27001
Coalfire logo

Coalfire

Compliance-focused cybersecurity advisory firm and FedRAMP 3PAO specializing in penetration testing that meets stringent regulatory requirements.

50
Score
LOCWestminster, Colorado, United States
Web ApplicationNetworkCloud+5
SOC 2FedRAMP 3PAOPCI QSA+1
WithSecure logo

WithSecure

Leading European cybersecurity firm offering penetration testing with deep expertise in EU regulatory compliance including GDPR, NIS 2, and TIBER-EU.

49
Score
LOCHelsinki, Finland
Web ApplicationNetworkCloud+7
CRESTISO 27001
Claranet logo

Claranet

CREST and CHECK-accredited European managed services provider delivering penetration testing with deep infrastructure and cloud hosting expertise.

48
Score
LOCLondon, United Kingdom
Web ApplicationNetworkMobile App+5
CRESTCHECKISO 27001+1
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.

47
Score
LOCSan Francisco, California, United States
Web ApplicationAPIMobile App+3
SOC 2ISO 27001FedRAMP 3PAO
Integrity360 logo

Integrity360

CREST-accredited pan-European cybersecurity services provider delivering penetration testing and managed security from Dublin with a strong UK and Ireland presence.

44
Score
LOCDublin, Ireland
Web ApplicationNetworkMobile App+6
CRESTISO 27001SOC 2
SEC Consult logo

SEC Consult

Leading European cybersecurity consultancy from Vienna with a prolific vulnerability research program and deep expertise in IoT and embedded systems security.

43
Score
LOCVienna, Austria
Web ApplicationNetworkMobile App+7
ISO 27001
CrowdStrike logo

CrowdStrike

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

43
Score
LOCAustin, Texas, United States
Red TeamingNetworkWeb Application+5
SOC 2ISO 27001
IOActive logo

IOActive

Elite boutique security consultancy specializing in IoT, SCADA/ICS, embedded systems, and hardware security research with world-renowned researchers.

42
Score
LOCSeattle, Washington, United States
Web ApplicationNetworkIoT+7
OSCP Employer
Secureworks logo

Secureworks

Dell Technologies-backed cybersecurity firm with elite Counter Threat Unit intelligence informing enterprise penetration testing and adversary simulation.

41
Score
LOCAtlanta, Georgia, United States
Web ApplicationNetworkCloud+7
SOC 2ISO 27001
Rhino Security Labs logo

Rhino Security Labs

Cloud security penetration testing specialists known for the Pacu AWS exploitation framework and deep expertise across AWS, Azure, and GCP environments.

41
Score
LOCSeattle, Washington, United States
CloudWeb ApplicationNetwork+4
SOC 2
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.

40
Score
LOCNew York, New York, United States
Web ApplicationNetworkRed Teaming+5
OSCP Employer
Bugcrowd logo

Bugcrowd

Leading crowdsourced security platform offering managed bug bounty programs and crowd-powered penetration testing with hundreds of thousands of ethical hackers.

40
Score
LOCSan Francisco, California, United States
Web ApplicationAPIMobile App+3
SOC 2ISO 27001
Aon Cyber Solutions logo

Aon Cyber Solutions

Cybersecurity consulting division of global insurance leader Aon, uniquely combining penetration testing with cyber risk quantification and insurance expertise.

36
Score
LOCLondon, United Kingdom
Web ApplicationNetworkCloud+5
ISO 27001SOC 2
BreachLock logo

BreachLock

Cloud-based Penetration Testing as a Service platform combining AI-driven automation with expert manual testing at accessible price points.

33
Score
LOCNew York, New York, United States
Web ApplicationNetworkAPI+4
SOC 2ISO 27001
Cure53 logo

Cure53

Berlin-based specialists in web security, browser security, and cryptographic auditing, trusted by the world's leading VPN providers and privacy tools.

32
Score
LOCBerlin, Germany
Web ApplicationAPISource Code Review+2
Cobalt logo

Cobalt

Pioneer of Pentest as a Service, delivering fast, platform-based penetration testing with a vetted global community of security researchers.

29
Score
LOCSan Francisco, California, United States
Web ApplicationNetworkAPI+2
SOC 2

ISO 27001 FAQs

Does ISO 27001 require penetration testing?+

While not explicitly mandated, penetration testing is strongly recommended under Annex A controls A.8.8 (management of technical vulnerabilities) and A.18.2.1 (independent review of information security). Most certification auditors expect to see evidence of regular pen testing.

How often should pen testing be done for ISO 27001?+

Annual penetration testing is the standard expectation, with additional testing after significant changes to systems within the ISMS scope.

What scope should pen testing cover for ISO 27001?+

Testing should cover systems and networks within the ISMS scope, including infrastructure, applications, and any systems that process, store, or transmit information covered by the ISMS.