Thick client applications are programs that can operate independently without a constant server connection by containing locally stored resources, unlike thin clients. Thick clients are commonly used for interacting with private data and pose security risks if they are legacy applications. Some common vulnerabilities of thick clients include sensitive data disclosure, denial of service attacks, improper access control, and insecure storage. Penetration testing of thick clients involves gathering information on technologies, behaviors, user inputs, and security techniques used, then mapping, enumerating, scanning for vulnerabilities, identifying and assessing vulnerabilities, and attempting exploitation of potential vulnerabilities found. Elanus Technologies specializes in assessing thick client security through static analysis, dynamic analysis, penetration testing, configuration reviews, and network traffic analysis.