The discovery of a new ransomware family named Osiris in late 2025 serves as a stark reminder that the cyber extortion landscape is not just persistent but is actively accelerating in its complexity and lethality. Modern ransomware is no longer a simple act of digital vandalism; it has evolved into a multi-faceted operation that combines data theft, system paralysis, and psychological pressure. These advanced tactics, which blend bespoke malware with legitimate system tools, represent a critical and ongoing threat to organizations of all sizes across the globe.
This analysis will deconstruct the sophisticated nature of these threats by first examining the anatomy of the recent Osiris attack, which provides a clear blueprint for modern extortion campaigns. From there, the discussion will broaden to analyze the advanced tactics, techniques, and procedures that define the current threat ecosystem. Finally, it will look toward the future by identifying key trends and concluding with actionable strategies that organizations must adopt to build a resilient defense against this ever-adapting adversary.
The Anatomy of a Modern Ransomware Attack
The Emergence of the Osiris Ransomware Family
In November 2025, cybersecurity researchers from Symantec and Carbon Black uncovered a new ransomware strain, dubbed Osiris, during their investigation of an attack on a major food service franchisee in Southeast Asia. Initial analysis confirmed that this malware is an entirely new family, bearing no code or architectural resemblance to the Locky variant that used the same name in 2016. This distinction underscores the continuous innovation within the cybercrime community, where new and potent tools are constantly being developed and deployed.
While the creators of Osiris remain unknown, forensic evidence points to a potential connection with the established INC ransomware group. This link is based on a pattern of shared tactics, techniques, and procedures (TTPs) observed during the attack. Specifically, the threat actors exfiltrated stolen data to Wasabi cloud storage and used a specific variant of the Mimikatz credential-stealing tool saved as “kaz.exe,” both of which are known signatures of INC operators. This suggests either a direct link or a shared playbook among highly skilled cybercriminal groups.
A Case Study: The Attack on a Southeast Asian Franchisee
The real-world deployment of Osiris against the franchisee demonstrated a methodical, multi-stage intrusion process. Before deploying the final encryption payload, the attackers first established a foothold, moved laterally across the network, and exfiltrated sensitive corporate data, maximizing their leverage for the extortion phase. This dual approach of data theft and encryption has become the standard for sophisticated ransomware campaigns.
A technical breakdown of the Osiris payload reveals its formidable capabilities. It utilizes a hybrid encryption scheme, combining the speed of symmetric algorithms with the security of asymmetric cryptography, and generates a unique key for each file it encrypts, making manual recovery nearly impossible. Furthermore, Osiris is highly configurable, allowing attackers to specify target folders, terminate critical processes like Microsoft Office, and stop essential services. Its default programming targets system recovery tools, including the Volume Shadow Copy Service (VSS) and Veeam backup software, effectively crippling an organization’s ability to restore its systems from local copies.
Analysis of Advanced Attacker Tactics, Techniques, and Procedures
The Osiris attack is emblematic of a broader trend toward more sophisticated methods, as observed by researchers at Symantec and Carbon Black. Modern threat actors are increasingly moving away from single-use malware, instead adopting a blended approach that combines custom-built tools with legitimate software. This “living off the land” strategy allows them to operate stealthily within a compromised network, evade traditional security measures, and maximize the impact of their final payload.
This evolution in TTPs necessitates a corresponding shift in defensive strategies. Simply blocking known malicious files is no longer sufficient. Security teams must now focus on behavioral analysis, monitoring for the anomalous use of legitimate tools and identifying the subtle signs of a prolonged, hands-on-keyboard intrusion before it culminates in a catastrophic ransomware event.
The Weaponization of Custom Drivers in BYOVD Attacks
A particularly advanced technique observed in the Osiris incident was the use of a custom-built malicious driver named POORTRY in a Bring Your Own Vulnerable Driver (BYOVD) attack. The driver’s sole purpose was to escalate privileges on the compromised system and forcefully terminate security software, rendering endpoint protection solutions blind to the subsequent stages of the attack.
This approach marks a significant evolution from traditional BYOVD attacks, which typically exploit a pre-existing vulnerability in a legitimate, third-party driver. By developing and deploying their own malicious driver, the attackers demonstrated a higher level of technical skill and resourcefulness. This bespoke method is more difficult to detect and defend against, as it does not rely on known vulnerabilities that may already be patched or monitored by security vendors.
The Strategic Abuse of Dual-Use and Legitimate Tools
The Osiris operators made extensive use of the “living off the land” methodology to conduct their attack with minimal risk of detection. By leveraging dual-use tools—legitimate software that can be used for both administrative and malicious purposes—they were able to blend their activities with normal network traffic. This tactic is highly effective because it makes distinguishing malicious actions from benign administrative tasks incredibly challenging for security teams.
Among the tools used in this campaign were Rclone, a command-line program for managing files on cloud storage, which was used to exfiltrate stolen data. For network reconnaissance and lateral movement, the attackers employed Netscan and Netexec. To maintain persistent access, they deployed remote access tools like MeshAgent and a custom version of RustDesk. This strategic use of legitimate software highlights the need for robust monitoring and anomaly detection that goes beyond signature-based malware scanning.
The Future Outlook of the Ransomware Ecosystem
Reflecting on ransomware activity throughout 2024 and 2025 provides a clear trajectory for the future of this threat. The landscape is not static; it is a dynamic ecosystem where threat actors constantly refine their evasion techniques, diversify their attack vectors, and even engage in deception to achieve their goals. The slight but steady increase in publicly claimed attacks, reaching 4,737 in 2025, confirms that ransomware remains a lucrative and persistent enterprise for cybercriminals.
The coming years will likely see an escalation in these trends. Attackers will continue to develop more sophisticated malware designed to bypass next-generation security controls, while the exploitation of vulnerabilities in widely used software will remain a primary entry point. The broader implications for cybersecurity defense are clear: organizations must move toward a more proactive, intelligence-driven security posture that anticipates and adapts to these evolving threats.
Evolving Evasion Tactics and Diversified Access Vectors
Leading ransomware groups are continuously evolving their deployment models to bypass modern security controls. For example, the LockBit 5.0 variant introduced a two-stage deployment process, separating the initial loader from the main encryption payload to reduce its signature and evade detection. Similarly, the Akira group has been observed exploiting VPN vulnerabilities to deliver loaders like Bumblebee, demonstrating a continued focus on compromising the network perimeter.
These examples show that threat actors are diversifying their initial access methods well beyond simple phishing emails. They are actively scanning for and exploiting unpatched vulnerabilities in public-facing infrastructure, targeting insecure Remote Desktop Protocol (RDP) configurations, and using complex social engineering lures. This multi-pronged approach to intrusion requires a defense-in-depth strategy that secures all potential entry points into an organization’s network.
The Rise of Deception, Flaws, and Cross-Platform Threats
Emerging trends also point toward a more complex and deceptive threat environment. False flag operations, such as those suspected with the Sicarii RaaS group, are used to obscure the true origin and motives of attackers. This adds a layer of misdirection that can complicate attribution and incident response efforts.
Simultaneously, the technical proficiency of ransomware developers varies. The Obscura variant, for instance, contains a critical flaw that prevents it from saving the decryption keys for files larger than 1GB, making recovery impossible even if the ransom is paid. On the other end of the spectrum, the development of cross-platform ransomware written in modern languages like Rust is on the rise. These variants can target both Windows and Linux environments, expanding the potential attack surface and posing a significant threat to organizations with heterogeneous IT infrastructure.
Conclusion and Strategic Recommendations for Mitigation
The analysis of the Osiris ransomware and the broader ecosystem trends underscores the severe and adaptive nature of modern cyber extortion campaigns. The attack playbook has shifted definitively from simple encryption to a complex, multi-stage operation involving data exfiltration, advanced evasion techniques, and the strategic misuse of legitimate tools. This evolution has created a more dangerous and resilient threat that demands a more sophisticated defensive posture from organizations.
To effectively counter these targeted attacks, a multi-layered and proactive security strategy is essential. Organizations are strongly advised to implement robust measures, including the rigorous monitoring for the misuse of dual-use tools to detect “living off the land” activity. Securing RDP services and enforcing multi-factor authentication across all critical systems are crucial steps to hardening the network perimeter. Furthermore, implementing application allowlisting to prevent unauthorized executables and maintaining immutable, off-site backups remain fundamental pillars for ensuring operational resilience and data recoverability in the face of a destructive attack.
