An In-Depth Analysis of Conti Ransomware: Tactics and Techniques
Introduction
Ransomware attacks have evolved from opportunistic schemes to highly sophisticated operations, often orchestrated by well-funded and organized cybercrime syndicates. Among these, the Conti ransomware group stands out as one of the most notorious and successful. With estimated revenues exceeding $200 million, Conti has inflicted substantial damage on businesses worldwide. In this article, we delve into the inner workings of Conti, exploring their tactics, techniques, and procedures (TTPs), as well as the tools they employ to execute their attacks. Our analysis is based on leaked internal documentation, offering a rare glimpse into the operations of a modern ransomware group.
The Rise of Conti Ransomware
Conti emerged on the cybercrime scene in 2020, quickly establishing itself as a formidable threat. The group is believed to be managed by Wizard Spider, a Russia-based cybercrime organization also linked to the Ryuk ransomware. Conti operates under a ransomware-as-a-service (RaaS) model, where affiliates are recruited to distribute the ransomware in exchange for a share of the profits. This decentralized approach has allowed Conti to scale rapidly, with affiliates targeting organizations across various industries.
Ransomware-as-a-Service: The Business of Conti
Conti’s operations resemble those of a legitimate business, complete with hierarchical structures, specialized roles, and even a “CEO” overseeing the activities. New affiliates undergo an onboarding process where they are provided with detailed manuals and training on the group’s methodologies. These documents outline everything from how to infiltrate networks to how to evade detection and maximize ransom payouts.
Conti’s success can be attributed to several factors:
- Professionalism: The group operates with a level of professionalism uncommon in the cybercrime world. Affiliates are expected to adhere to strict protocols, and the group’s leaders provide continuous support and updates.
- Rapid Exploitation of Vulnerabilities: Conti is known for quickly adopting new exploits, allowing them to stay ahead of security patches and defenses.
- Use of Open-Source and Legitimate Tools: Conti leverages a combination of off-the-shelf open-source tools and legitimate software to stage attacks, which helps them avoid detection by traditional security measures.
Conti’s Tactics, Techniques, and Procedures (TTPs)
The leaked Conti documentation reveals a comprehensive list of TTPs that the group employs throughout their attack lifecycle. Understanding these can help organizations bolster their defenses and respond more effectively to ransomware incidents.
Initial Access and Lateral Movement
Conti’s primary goal is to gain a foothold within the target network and move laterally until they reach the domain controller (DC). The group typically exploits weak credentials, unpatched vulnerabilities, and social engineering tactics to gain initial access. Some of the key vulnerabilities they have exploited include:
- PrintNightmare (CVE-2021-1675/CVE-2021-34527): This critical vulnerability in the Windows Print Spooler service allows attackers to execute remote code on affected systems, enabling them to escalate privileges and move laterally within the network.
- ZeroLogon (CVE-2020-1472): ZeroLogon is a vulnerability in the Netlogon protocol that allows attackers to impersonate any computer, including the domain controller, and gain administrator privileges.
- EternalBlue (MS17-010): This exploit, made infamous by the WannaCry ransomware, targets a vulnerability in the SMB protocol, allowing for remote code execution and lateral movement across a network.
Once inside the network, Conti operators methodically work to steal credentials and expand their access. They aim to gain domain administrator privileges, enabling them to control the entire network. This often involves accessing and exfiltrating sensitive data such as login logs, DNS records, and password hashes.
Post-Exploitation Activities
After gaining control over critical network assets, Conti operators focus on maintaining and deepening their access. This involves leveraging various privilege escalation exploits, many of which are well-known but remain effective due to poor patch management in target organizations. Some of the vulnerabilities they exploit for post-exploitation activities include:
- CVE-2018-8120: A vulnerability in Windows that allows attackers to execute arbitrary code with elevated privileges.
- CVE-2019-0841: A privilege escalation vulnerability in Windows that allows attackers to gain elevated privileges.
- CVE-2021-1675: Also part of the PrintNightmare vulnerability, it can be used for privilege escalation on Windows systems.
By exploiting these and other vulnerabilities, Conti operators ensure they can maintain their foothold in the network for extended periods, even as defenders attempt to remediate the intrusion.
Tools and Command-Line Utilities
Conti’s toolkit is a blend of well-known offensive security tools, legitimate software repurposed for malicious activities, and custom-developed scripts. Some of the key tools used by Conti include:
- Cobalt Strike Beacon: A popular post-exploitation tool that provides attackers with a command-and-control (C2) framework, allowing them to execute commands on compromised machines, escalate privileges, and move laterally within the network.
- ATERA Agent: A legitimate remote management tool that Conti uses for persistence, allowing them to maintain remote access to compromised systems without raising suspicion.
- Ngrok: A legitimate tool that creates secure tunnels to localhost, often used by Conti to exfiltrate data or establish C2 channels without triggering alerts from security monitoring systems.
- RClone: An open-source tool used by Conti to exfiltrate data from compromised systems, often to cloud storage services.
- Armitage: A graphical cyber attack management tool that integrates with Metasploit, used by Conti for post-exploitation tasks such as network reconnaissance and exploitation.
- Mimikatz: A well-known tool for dumping plaintext passwords, hashes, PINs, and Kerberos tickets from memory, enabling Conti to gain access to additional accounts and escalate privileges.
- PowerShell: Conti heavily relies on PowerShell scripts to automate various tasks, such as disabling security features like Windows Defender, conducting reconnaissance, and executing payloads.
- Kerberoasting: A technique that involves extracting service account credentials from Active Directory and cracking them offline. Conti uses this method to obtain high-privilege credentials.
Evading Detection
Conti is adept at avoiding detection by leveraging legitimate tools and living-off-the-land techniques. By using tools like ATERA and AnyDesk, which are commonly used in legitimate IT environments, Conti can blend in with normal network traffic and avoid triggering alarms. They also employ obfuscation techniques, such as encoding their payloads or using custom encryption schemes, to evade signature-based detection methods.
Protecting Your Organization Against Ransomware
Given the sophistication and persistence of groups like Conti, defending against ransomware attacks requires a multi-layered approach. Here are some strategies organizations can implement to protect themselves:
- Patch Management: Regularly update and patch all systems, especially those that are publicly accessible or critical to your operations. Vulnerabilities like ZeroLogon and EternalBlue should be addressed as a priority.
- Network Segmentation: Segment your network to limit lateral movement. Critical assets, such as the domain controller, should be isolated from less secure parts of the network.
- Multi-Factor Authentication (MFA): Implement MFA across all critical systems and services to reduce the risk of compromised credentials being used to gain access.
- Endpoint Detection and Response (EDR): Deploy EDR solutions to monitor and respond to suspicious activity on endpoints. EDR tools can help detect and stop ransomware before it has a chance to execute.
- User Education and Training: Educate employees about phishing and social engineering attacks, which are common vectors for ransomware. Regular training and simulated phishing exercises can help reduce the risk of initial compromise.
- Data Backups: Regularly back up important data and ensure backups are stored securely offline. In the event of a ransomware attack, having reliable backups can significantly reduce downtime and data loss.
- Incident Response Plan: Develop and regularly test an incident response plan that includes procedures for detecting, containing, and recovering from ransomware attacks. Having a well-prepared plan can make the difference between a quick recovery and a prolonged outage.
Conclusion
The Conti ransomware group represents the epitome of modern cybercrime—organized, professional, and relentlessly effective. By understanding their tactics and the tools they use, organizations can better prepare themselves to defend against such threats. While the fight against ransomware is ongoing, staying informed and proactive is key to minimizing the risk and impact of an attack.
For organizations that feel overwhelmed by the complexity of ransomware defense, seeking professional assistance is a prudent step. Our experts can help assess vulnerabilities, implement robust defenses, and respond effectively if an attack occurs.
Don’t wait until it’s too late—take action now to protect your business from the growing threat of ransomware.