What Calif does

Calif is a Palo Alto-based cybersecurity consulting firm specializing in AI-assisted vulnerability research and penetration testing for enterprise technology clients. Founded by Thai Duong (former Google security engineer and co-discoverer of the BEAST, CRIME, and POODLE SSL attacks) and An Trinh, the firm combines elite human security researchers with frontier AI models — notably Anthropic's Claude Mythos and OpenAI's GPT models — to identify critical vulnerabilities in widely deployed software. Its two branded service lines are "attack.sh" (AI-augmented vulnerability discovery and exploit development) and "defend.sh" (translation of vulnerability findings into production-grade defensive systems).

The firm operates a professional services model with quote-based enterprise pricing, engaging directly with clients on red team engagements, penetration tests, and vulnerability research collaborations. Its named customer roster includes Google, Anthropic, OpenAI, CoreWeave, Wiz, Cursor, Chainguard, Lightspark, Cresta, and a portfolio of Vietnamese financial institutions. Calif is a core partner in OpenAI's Daybreak/Patch the Planet initiative and Anthropic's Project Glasswing, and is an initial recipient of OpenAI's $10 million Trusted Access for Cyber API credits program.

Calif has no disclosed venture funding and operates as a founder-led boutique firm in the 11-50 employee range. Its market positioning rests on individual researcher credibility (multiple Pwnie Awards, advisory relationships with Michał Zalewski and Parisa Tabriz), high-profile public vulnerability disclosures including the 29-year-old Squid Proxy flaw (Squidbleed/CVE-2026-47729) and the first Apple M5 kernel Memory Integrity Enforcement bypass, and co-development relationships with frontier AI labs. Go-to-market is hybrid: enterprise field sales for paid engagements layered with community-led content marketing via technical blog posts, conference talks, and earned media that drives inbound demand.

Name

Calif

Legal name

Calif

Website

https://calif.io

Company type

Private

Founded year

2020

Operating status

Operating

Headcount range

51–100 employees

Short description

Calif is a Palo Alto-based boutique cybersecurity firm that combines elite human security researchers with frontier AI models (Anthropic Claude Mythos, OpenAI) to perform penetration testing and vulnerability research for enterprise technology clients.

Ownership category

akta.pro rank

Product category

Cybersecurity Consulting and Penetration Testing Services

NAICS

Security Systems Services (56162), Investigation and Security Services (5616), Scientific Research and Development Services (5417)

SIC

Services-Engineering, Accounting, Research, Management (8700), Services-Engineering Services (8711)

akta.pro primary industry

Penetration Testing Platforms (PTaaS) (HDADAHAG)

akta.pro secondary industries

Breach & Attack Simulation (BAS) (HDADAHAD), Application Security Engineering (DevSecOps, AppSec Remediation) (BPAEAFAI)

Keywords

• Penetration testing
• Vulnerability research
• Red team services
• Security engineering
• AI-assisted cybersecurity

Headquarters

HQ city

Sunnyvale

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales

Revenue model

1. Security Assessment and Penetration Testing Services: Professional red teaming and security assessment engagements for enterprise clients. Testimonials indicate high-value, specialized security testing engagements with top-tier clients including Google, financial institutions, and AI companies.
2. Vulnerability Research Partnerships: Collaborative vulnerability research initiatives with AI companies (Anthropic, OpenAI) and major open-source foundations to discover and remediate security flaws in critical infrastructure.

Go-to-market motion2 records

Distribution channels1 record

Marketing channels6 records

Core offering

Calif is a security research firm offering two integrated professional services: attack.sh for AI-assisted vulnerability discovery and proof-of-concept exploit development using frontier AI models, and defend.sh for translating findings into hardened production defenses. The firm performs red team engagements, penetration testing, and collaborative vulnerability research for enterprise technology clients.

Product overview

Calif is a security research firm offering two integrated services: attack.sh for AI-powered vulnerability discovery using frontier models from Anthropic and OpenAI, and defend.sh for translating findings into hardened defenses. The company conducts red team and penetration testing engagements, focusing on frontier vulnerability research that identifies critical flaws in widely-used software before malicious actors can exploit them.

Differentiator

Problem solved

Functional benefit

Products and services

• attack.sh

Quantifiable outcome

• Over 10,000 vulnerabilities discovered in open-source software using AI-augmented research
• +4 more outcomes

Named customers9 records

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability3 records

Feature3 records

Partnerships

Six partnerships are on record, tiered core and secondary.

• OpenAIcoreStrategic or Co-development Partner · 22 June 2026Calif participates in OpenAI's Daybreak cybersecurity initiative and Patch the Planet program as a security engineering partner. They contribute vulnerability research expertise alongside Trail of Bits and provide triage and coordinated disclosure support for open-source projects including cURL, Python, Go, Sigstore, and others. Calif also received API credits through OpenAI's Cybersecurity Grant Program as part of the Trusted Access for Cyber initiative.
• Trail of BitscoreStrategic or Co-development Partner · 22 June 2026Calif co-founded the Patch the Planet initiative with Trail of Bits as part of OpenAI's Daybreak program. Both companies provide security engineering support, with Trail of Bits contributing human expert review alongside AI-assisted vulnerability research to help open-source maintainers identify and remediate security flaws.
• HackerOnesecondaryTechnology or Integration · 22 June 2026Calif collaborates with HackerOne in the Patch the Planet initiative to support vulnerability classification and coordinated disclosure for open-source projects. HackerOne provides platform capabilities for managing bug bounty programs and responsible disclosure processes.
• OpenAI Trusted Access for Cyber ProgramcoreStrategic or Co-development Partner · 16 April 2026Calif is an initial recipient of OpenAI's $10 million API credits grant program as part of the Trusted Access for Cyber initiative, alongside Socket, Semgrep, and Trail of Bits. This program provides access to GPT-5.4-Cyber model capabilities to strengthen cyber defense capabilities for under-resourced defenders.
• AnthropiccoreStrategic or Co-development PartnerCalif uses Anthropic's Claude Mythos AI model (as part of Project Glasswing) for vulnerability discovery research. They demonstrated the model's capabilities by discovering a macOS kernel exploit on Apple M5 chips and a 29-year-old Squid Proxy vulnerability. Calif's research helped showcase Mythos's effectiveness in finding critical security flaws.
• GooglesecondaryOthersGoogle's security team has engaged with Calif on various security assessments and vulnerability research. Security researcher Andy Nguyen praised Calif's technical competence and high-quality findings. The relationship is mutually beneficial for talent exchange and research collaboration.

Scale indicators3 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Trail of Bits: Elite security research and consulting firm specializing in applied cryptography, blockchain, and AI/ML security. Direct peer to Calif — co-founded OpenAI's Patch the Planet initiative alongside Calif, both are initial recipients of OpenAI's Trusted Access for Cyber grant, and both serve enterprise technology clients with high-end security research engagements.
• Semgrep: Application security platform combining code analysis with AI-assisted vulnerability detection. Direct peer to Calif — both are initial recipients of OpenAI's $10M Trusted Access for Cyber program, both target AI-augmented code security for enterprise developer teams, and both compete for the same budget line item (AppSec / DevSecOps).
• Socket: Supply chain security company using AI to detect malicious packages and vulnerabilities in open-source dependencies. Direct peer to Calif — both are initial OpenAI Trusted Access for Cyber recipients, both focus on securing open-source ecosystems with AI, and both serve similar enterprise technology customers.
• Bishop Fox: Top-tier offensive security firm specializing in penetration testing, red teaming, and vulnerability research for Fortune 500 and enterprise technology clients. Direct peer to Calif in boutique pentesting — comparable positioning as a high-end, technically elite pen test vendor serving similar technology and financial enterprise customers.
• Cure53: Berlin-based boutique security research firm specializing in penetration testing and security audits for software, browsers, and web applications. Direct peer to Calif in elite boutique security research — both serve high-end technology clients (browser vendors, open-source foundations) and operate with small teams of world-class researchers.
• NetSPI: Large-scale penetration testing and attack surface management platform serving enterprise customers across financial services, healthcare, and technology. Direct peer to Calif in penetration testing services — broader portfolio and larger scale but competes for the same enterprise pen-testing RFPs.
• Synack: Penetration testing platform combining a vetted researcher community with platform-enabled delivery for enterprise security testing. Direct peer to Calif in elite pen-testing — both target enterprise security buyers, both emphasize researcher quality, and both compete in the security testing services category.

Broad incumbents

• NCC Group: Global, publicly-listed cybersecurity consulting firm offering a broad portfolio of services including penetration testing, red teaming, threat intelligence, and managed security. Broad incumbent peer to Calif — much larger scale and broader service mix, but competes in the same enterprise pentesting RFP market, particularly for financial services and large technology customers.
• HackerOne: Bug bounty and vulnerability disclosure platform connecting enterprises with a global community of security researchers. Broad incumbent peer to Calif — Calif collaborates with HackerOne in the Patch the Planet initiative, and the platforms compete for similar security testing / vulnerability discovery budgets at large enterprises.
• Mandiant (Google Cloud): Google-owned incident response and cyber threat intelligence firm with a large security consulting practice including red team, pen testing, and vulnerability research. Broad incumbent peer to Calif — both serve Google's security ecosystem (per Calif's customer roster) and compete for the same enterprise security testing budgets at scale.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks5 records

Key highlights7 records

Customer concentration

• Xx.com/calif_io
• GitHubgithub.com/califio
• LinkedInlinkedin.com/company/califio

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Calif