XCSSET is a sophisticated family of malware that targets macOS systems, primarily spreading through compromised Xcode development projects. Once installed, XCSSET can steal sensitive user data, capture screenshots, inject malicious code into websites, and bypass browser security features. Its modular design allows attackers to update or expand its capabilities after initial infection, making it particularly dangerous. XCSSET is notable for exploiting vulnerabilities unique to macOS and for targeting software developers, which increases the risk of widespread distribution through shared code projects.