Operation RAT Cook is a cyber espionage campaign attributed to Chinese Advanced Persistent Threat (APT) actors that leverages social engineering tactics by using fake leaks of popular media content, specifically purported Game of Thrones episodes, as bait to lure victims. The campaign is characterized by the distribution of malicious payloads disguised as leaked episodes or related content, aiming to entice targets into downloading or interacting with these files. Once engaged, the malware—typically Remote Access Trojans (RATs)—can establish persistent access to the victim's system, enabling data exfiltration, surveillance, and further network compromise. The use of culturally relevant and highly anticipated media content as lures is a common tactic in APT campaigns to increase the likelihood of victim interaction. Although the campaign was first identified in 2017 and is marked with a low severity rating, the underlying threat remains significant due to the stealthy nature of RATs and the potential for long-term espionage. The campaign does not specify affected software versions or known exploits, indicating that the primary attack vector is social engineering rather than exploiting technical vulnerabilities. The absence of public indicators or patch links suggests that detection relies heavily on behavioral analysis and threat intelligence sharing. Overall, Operation RAT Cook exemplifies the use of OSINT and cultural context in crafting targeted phishing campaigns by state-sponsored actors.

For European organizations, the impact of Operation RAT Cook could be substantial, particularly for entities involved in media, entertainment, government, and critical infrastructure sectors that are often targeted by Chinese APT groups for espionage purposes. Successful compromise via this campaign could lead to unauthorized access to sensitive information, intellectual property theft, and potential disruption of operations. The use of popular cultural content as bait increases the risk of inadvertent infection by employees who may be tempted to access unauthorized or pirated media. Given the stealthy nature of RATs, compromised systems might remain undetected for extended periods, allowing attackers to conduct prolonged surveillance and data exfiltration. Although the campaign is rated low severity, the potential for lateral movement within networks and the targeting of high-value assets elevates the risk profile for European organizations, especially those with weak user awareness and insufficient endpoint protection.

Mitigation should focus on enhancing user awareness and technical defenses tailored to combat social engineering and RAT infections. Specific recommendations include: 1) Conduct targeted security awareness training emphasizing the risks of downloading unauthorized media content and recognizing phishing lures that exploit popular culture. 2) Implement strict policies restricting the use of unauthorized software and media downloads on corporate networks. 3) Deploy advanced endpoint detection and response (EDR) solutions capable of identifying anomalous behaviors associated with RATs, such as unusual network connections or process activities. 4) Utilize network segmentation to limit lateral movement in case of compromise. 5) Maintain up-to-date threat intelligence feeds to detect emerging APT campaigns and indicators of compromise related to Operation RAT Cook. 6) Enforce multi-factor authentication and least privilege principles to reduce the impact of credential theft. 7) Regularly audit and monitor network traffic for suspicious outbound connections that may indicate data exfiltration attempts. These measures, combined with proactive incident response planning, will help mitigate the risks posed by this campaign.