Offensive security firms differ less in the names of their services than in how those services are delivered. Before comparing firms, decide three things: what you need tested (applications, networks, cloud, identity, applications built on a large language model (LLM), or a full adversary simulation), whether you want a scoped engagement or a continuing program, and how much of the testing must be performed by named operators rather than a platform. Then compare proposals on scope, people, retest terms and a sample report.
Scoped consulting engagements run manually by operators, under a written statement of work, rules of engagement and signed authorization. Critical findings are raised through a named escalation contact when found.
Scope
Network, web application and application programming interface testing, cloud assessments, red and purple team exercises, social engineering, AI red teaming, and compliance evidence mapping.
Buyer fit
Security and engineering leaders who want a named team, findings ranked by what an attacker actually reaches, and AI applications tested as deployed systems rather than models.
What to confirm
— Which operators will be on your engagement
— The retest window and which findings it covers
— Whether your compliance evidence needs are in scope
Red Cell takeOur own entry: a San Diego firm built around manual testing, a report written for two readers, and one included retest of the agreed findings.
Publicly describes human-led offensive security services combined with its own platform, Cosmos, which it operates and manages as part of its services, with results delivered through a client portal.
Scope
Publicly lists application, network, cloud, hardware and product security testing, AI and LLM security assessment, continuous threat exposure management, red teaming, social engineering and ransomware readiness.
Buyer fit
Publicly lists industries including energy and utilities, financial services, healthcare, manufacturing, and media and entertainment.
What to confirm
— Which parts of AI-powered testing are automated and which are done by named testers
— Whether retesting is included for every engagement type, and within what window
— How often humans review findings in continuous testing
Red Cell takeA broad option for organizations that want scoped testing and a managed continuous program from the same firm.
Publicly describes penetration testing, consulting and defensive security services, including continuous penetration testing, a managed security operations service, incident response retainers and training.
Scope
Publicly lists penetration testing of applications, networks and cloud, web application testing, AI security assessments, social engineering, blockchain security, incident response and governance, risk and compliance.
Buyer fit
Describes serving organizations across a wide range of sizes; specific industries are not stated on its site.
What to confirm
— Whether retesting of fixed findings is included
— How continuous testing differs from a point-in-time test in cadence and reporting
— Whether AI assessments cover LLM features inside your own application
Red Cell takeWorth shortlisting for teams that want offensive testing alongside defensive and training services from one provider.
Publicly describes manual penetration testing delivered as a service, with a dashboard for tracking findings, a shared chat channel, an attestation letter and free re-testing.
Scope
Publicly lists web application, mobile, cloud and infrastructure penetration testing, continuous penetration testing, red teaming as a service, social engineering, and LLM and AI penetration testing.
Buyer fit
Specific industries are not stated on its site.
What to confirm
— Who performs the testing, and the qualifications of the named tester
— The cadence and scope of continuous testing
— Whether LLM testing covers agents, tool use and retrieval in your application
Red Cell takeWorth a look for buyers who want a packaged service with a tracking dashboard and open-ended re-testing.
Publicly describes a hybrid of automated tools and manual testing by in-house specialists, with reports delivered through a client portal, alongside continuous penetration testing, managed services and incident response.
Scope
Publicly lists penetration testing, continuous testing, attack simulation, application, hardware and embedded, network, cryptography, cloud and blockchain security, AI testing, managed detection services and consulting.
Buyer fit
Publicly lists industries including financial services, public sector, health, energy, manufacturing, retail, transport, technology and legal services.
What to confirm
— Which AI and LLM attack classes its AI testing covers
— Whether retesting is included in standard and continuous engagements
— Which parts of an engagement are automated and which are manual
Red Cell takeSuited to large organizations that want testing, managed services and incident response under one contract.
Publicly describes penetration testing as a service (PTaaS) that combines human testers with purpose-built AI, offered as continuous or point-in-time testing through its own platform.
Scope
Publicly lists application, network, cloud, mainframe, hardware and AI and machine learning penetration testing, red team operations, social engineering, secure code review, threat modeling and attack surface management.
Buyer fit
References customers including cloud providers, banks, healthcare and technology companies.
What to confirm
— The retest terms under remediation testing: rounds and timeframe
— How work divides between the platform and human testers, and who signs off findings
— How continuous and point-in-time options differ for your systems
Red Cell takeA strong fit for organizations moving from one-off tests to a platform-managed testing program.
Publicly describes its Guard platform, combining automated agents with a team of offensive security engineers who review what the agents surface, sold as a subscription that includes a time-boxed annual assessment.
Scope
Publicly lists coverage of internet perimeter, web applications and APIs, LLM interfaces, cloud, code and CI/CD, internal networks, and social engineering, plus individual penetration testing, red and purple team services.
Buyer fit
Specific industries are not stated on its site; it lists compliance frameworks it addresses.
What to confirm
— Which findings come from agents and which from human operators, and how much review happens before reporting
— Whether AI testing is sold standalone, within the subscription, or both
— Which regulated environments the team has direct experience in
Red Cell takeBest considered by teams that want continuous exposure management with an annual assessment bundled in.
Publicly describes offensive testing, program building and practitioner training, alongside its BloodHound identity attack path platform, and states that the people who publish its research perform its engagements.
Scope
Publicly lists AI red teaming and AI security assessments, application security, penetration testing, identity attack path assessments, purple team and maturity assessments, and building internal red team programs.
Buyer fit
Publicly lists financial services, public sector and healthcare among its industries.
What to confirm
— Whether retesting of fixed findings is included
— What the report contains for each service type
— Whether AI red teaming covers your own applications and agents, the surrounding infrastructure, or both
Red Cell takeA natural shortlist entry for organizations where identity and attack paths are the central concern.
Publicly describes security reviews backed by research, with tooling handed to the client's engineers, embedded security engineering, and open publication of generalizable findings.
Scope
Publicly lists software assurance, AI and machine learning security, application security, blockchain, cryptography, security engineering, and research and development.
Buyer fit
Describes securing software, blockchains and cryptography for high-value targets; specific industries are not stated on its site.
What to confirm
— The publication policy for your engagement and whether you can opt out
— Whether the fix-review retest is included, and how long it is available
— Which regulated environments the firm has worked in
Red Cell takeThe specialist choice for deep code, cryptography and blockchain review rather than broad network testing.
Publicly describes phased consulting engagements from scoping to reporting, with a report walkthrough and a retest after remediation.
Scope
Publicly lists penetration testing, LLM assessment, red and purple teaming, social engineering, cloud and hardware testing, compliance risk assessments, hardening, incident response and AI governance.
Buyer fit
Names healthcare, finance, retail and manufacturing as example sectors.
What to confirm
— Whether the retest is included in scope, and within what window
— Whether the LLM assessment covers agents and tool calling as well as the model interface
— Whether any testing is subcontracted
Red Cell takeA good fit for teams that want offensive testing, hardening and incident response from one consulting partner.
Sources
Every statement about a firm other than Red Cell comes from the pages below, accessed on the evidence cutoff date.
Each firm publicly offers penetration testing or red teaming to US organizations and publishes enough detail about its services on its own website to describe its delivery model and scope. The list is a starting shortlist, not a complete survey of the market.
Why is Red Cell first?
Red Cell publishes this article and places itself first, as the publisher disclosure at the top states. That placement is the publisher's point of view. The remaining nine firms are listed alphabetically and are not scored or ranked against each other.
How current is this information?
Every statement about another firm comes from that firm's own website as of the evidence cutoff date shown at the top. Services change, so confirm anything that matters to your decision directly with the firm.
What is the difference between a platform and a consulting engagement?
Some firms deliver testing through their own platform, often combining automated discovery with human validation on a continuing basis. Others run scoped consulting engagements with a defined team, window and report. Many offer both. The what-to-confirm questions under each entry are designed to surface which model you would actually be buying.
Should we choose a firm based on a list like this?
Use it to build a shortlist, then compare written proposals. The scope, the people assigned, the retest terms and a sample report tell you more than any ranking.