Unit 221B is a cybersecurity firm that provides a range of security services and investigative capabilities. The company offers security testing services including penetration testing, red team exercises, and purple team operations with associated training programs. Their advisory services include virtual CISO offerings, security optimization programs with autonomous penetration testing, and audit compliance consulting. The company operates a managed threat and incident response practice, providing both proactive threat management and reactive incident response capabilities. Their threat intelligence services include executive operational security assessments and training. Unit 221B maintains an investigations practice that covers cybercrime attribution, expert witness services for legal proceedings, and specialized support for the gaming industry including anti-cheat copyright enforcement and online harassment protection. The company has developed eWitness, a product focused on digital evidence and investigations. Their research capabilities span DDoS attribution, cybercrime attribution, and analysis of criminal communities. The leadership team includes individuals with backgrounds in FBI prosecution, computer crime law development, signals intelligence, malware research, and digital forensics. Unit 221B serves clients requiring both offensive security testing and defensive incident response, as well as organizations needing investigative services for attribution and legal support. Their service portfolio addresses security testing, compliance, threat response, intelligence gathering, and specialized investigations across multiple sectors.