Viettel Compromise Assessment (VCS-CA) is a proactive security service that scans organizational systems to identify indicators of past or ongoing security breaches. The service examines systems for evidence of malware, unauthorized access, suspicious behaviors, backdoors, compromised accounts, and early signs of ransomware that may have bypassed traditional security defenses. The service uses threat hunting and forensic techniques to detect hidden threats, focusing on identifying attackers who may have remained undetected within systems for extended periods. The assessment process includes gathering organizational context and system architecture, conducting thorough evaluation and analysis of event logs, performing digital forensic investigations on compromised systems, and determining attack paths and exploited weaknesses. VCS-CA identifies malware and webshells, detects APT command and control connections, assesses security weaknesses and vulnerabilities, identifies policy violations and system misconfigurations, and detects suspicious open ports. The service is designed to be non-intrusive with minimal impact on business operations. The assessment provides detailed findings reports and recommendations for strengthening security posture based on identified weaknesses. The service leverages threat intelligence from telemetry data gathered from a regional ISP, SOC systems serving clients across multiple countries, and expertise from an incident response team handling ransomware attacks.