PRC-Linked Threat Actors Target REDCap Servers To Spy On U.S. Medical Research Organizations

Security researchers from Google Threat Intelligence Group (GTIG) uncovered a long-running cyber espionage campaign attributed to UNC6508, a PRC-linked threat actor that targeted medical, academic, and military research institutions across North America. The attackers remained undetected for more than a year while collecting sensitive information related to medical research, artificial intelligence, defense intelligence, cyber operations, and military strategy.

The campaign primarily focused on compromising REDCap (Research Electronic Data Capture) servers, a widely used platform for managing clinical research databases and surveys. After gaining access, the attackers deployed custom malware called INFINITERED, harvested credentials, established persistence, and later abused enterprise email compliance rules to exfiltrate sensitive communications.

Campaign Overview

The operation demonstrates a sophisticated attack chain combining exploitation of public-facing applications, credential theft, malware deployment, persistence mechanisms, and stealthy data exfiltration.

Key Objectives

Medical research intelligence
Artificial Intelligence research
Defense-related information
Military health research Public health policy data

Researchers observed the activity from September 2023 through November 2025, indicating a highly patient and well-resourced espionage operation.

High-level attack flow used by UNC6508 to compromise research institutions and steal sensitive information.

Initial Access Through REDCap Servers

Why REDCap Was Targeted

REDCap is extensively used across:

Hospitals
Clinical research organizations
Universities
Government research programs
Military health institutions

Because REDCap stores large volumes of research and patient-related information, it provides an attractive entry point for espionage-focused threat actors.

Researchers observed the attackers probing and exploiting vulnerable or legacy REDCap deployments exposed to the internet. Once access was obtained, they began internal reconnaissance and credential discovery activities.

Web Shell Deployment and Persistence

Following successful compromise, UNC6508 deployed a web shell identified as:

help.php

The web shell served multiple purposes:

Persistent access
File uploads
Command execution
Further malware deployment

This allowed the attackers to maintain long-term access even if passwords were changed or some security controls were implemented.

INFINITERED Malware Analysis

Three months after the initial intrusion, researchers observed deployment of a custom malware family called INFINITERED. This malware was specifically engineered to operate inside REDCap environments.

Modular architecture of INFINITERED malware used by UNC6508 to maintain persistence, harvest credentials, and execute commands within compromised REDCap environments.

Component 1 – Upgrade Interceptor

The malware monitors REDCap upgrade activities.

When administrators update REDCap, the malware automatically injects itself into newer versions, ensuring persistence across software upgrades

Component 2 – Credential Harvester

This module captures usernames and passwords entered into REDCap login pages.

Stolen credentials are stored within REDCap database tables and later retrieved by attackers.

Component 3 – Command-and-Control Backdoor

The third module acts as a fully functional backdoor.

Researchers found it could:

Execute shell commands
Upload files
Download files
Run SQL queries

Communication was hidden within HTTP cookie values, helping evade traditional detection mechanisms.

Abuse of Google Workspace for Data Exfiltration

One of the most interesting aspects of the campaign was the attackers’ use of legitimate Google Workspace functionality.

After obtaining administrative access, UNC6508 created a content compliance rule named:

Patroit

The rule automatically monitored emails containing specific keywords and forwarded matching messages to attacker-controlled Gmail accounts.

Attack Chain Breakdown

External Reconnaissance
Initial Compromise
Persistence
Privilege Escalation
Intelligence Gathering

Potential Impact on Organizations

Organizations affected by this campaign could experience:

Research Theft

Loss of valuable intellectual property and scientific research.

Strategic Intelligence Exposure

Disclosure of defense and geopolitical information.

Credential Compromise

Unauthorized access to enterprise systems.

Regulatory Risks

Exposure of regulated healthcare and research data.

Alternative Indicators of Compromise (IOCs)

IOC Category	Description
Web Shell	help.php
Malware Family	INFINITERED
Email Rule Name	Patroit
Activity	Unauthorized REDCap upgrades
Activity	Suspicious credential harvesting
Activity	Unexpected SQL queries
Activity	Abnormal Gmail forwarding rules
Activity	Unauthorized admin account access
Activity	HTTP cookie-based command execution
Activity	Unusual database access patterns

Security Recommendations

Upgrade REDCap Immediately

Remove legacy versions and apply the latest security updates.

Conduct Threat Hunting

Search for:

help.php
INFINITERED artifacts
Unauthorized admin activity
Credential harvesting indicators

The UNC6508 campaign highlights how modern nation-state threat actors are increasingly targeting research ecosystems to obtain strategic intelligence. By exploiting REDCap servers, deploying INFINITERED malware, and abusing legitimate cloud email features, the attackers maintained access for more than a year while collecting sensitive medical, defense, and technology research data. Organizations operating research platforms should prioritize patching, continuous monitoring, and proactive threat hunting to defend against similar espionage campaigns.