MDR Case Study: Interlock Ransomware

A new attack emerged in late 2024, Interlock ransomware. This variant distinguishes itself through its diverse array of attack methods, ranging from deceptive fake software updates and compromised websites to sophisticated "ClickFix" social engineering. This case study will delve into the intricacies of Interlock ransomware, exploring tactics, cross-platform capabilities, and prevention strategies.  

Interlock's stated mission is to expose cybersecurity weaknesses. For businesses, this illuminates the need for cybersecurity and the role of automated response strategies like Managed Detection and Response (MDR) in safeguarding your data.

What is Interlock?

Interlock ransomware, which emerged in late 2024, is a dangerous threat known for its double- extortion tactics. What differentiates Interlock is their opportunistic nature, using the following tactics:

• Fake software updates: Tricking users into downloading malicious updates for legitimate software like Google Chrome or Microsoft Edge. ‍
• Compromised websites: Distributing these fake updates via seemingly trustworthy sites. ‍
• "ClickFix" social engineering: Presenting fake error messages that prompt users to execute malicious commands.

Once inside, Interlock deploys tools like Remote Access Trojans (RATs) and credential stealers to move laterally within the network, often aiming for the domain controller to gain wide access. Before encryption, they exfiltrate sensitive data, sometimes moving to cloud storage.

This ransomware is notable for targeting both Windows and FreeBSD systems, Linux based open-source operating systems, and uses various evasion techniques to avoid detection. The Windows encryptor can also clear event logs and self-delete to hide its tracks.

How to Prevent Cyber Attacks?

A successful prevention strategy must address all possible known vectors for malware. The Net Friends team recommends overlapping systems to protect against attacks such as Interlock.

For example, a defense in depth strategy should include:

• Timely software updates to eliminate vulnerabilities left open to exploitation. ‍
• Strong passwords and MFA to prevent Interlock from exploiting stolen credentials.  ‍
• Server Hardening, ensures that changes to infrastructure are continually monitored.  ‍
• Immutable backups protect against Interlock’s deletion of shadow backups.

Given Interlock's varied attack methods, a strong defense is crucial. Interlock claims their mission is to highlight cybersecurity weaknesses, aiming to improve overall security. Their message is clear, if organizations are lax, they will be exploited.

The only truly effective response strategy is automation. Automating the detection of suspicious activity, cross-referencing it with known attack patterns, and swiftly isolating compromised systems or applications, allows for rapid detection. This critical, proactive approach is known as Managed Detection and Response (MDR). MDR services combine advanced technology with human expertise to continuously monitor, detect, investigate, and respond to cyber threats, significantly reducing the time to contain and remediate incidents.

How Can NetSafe® MDR Block Interlock?

Companies using NetSafe Managed Detection and Response to block Interlock should look at four main tactics:

1. Proactive Detection: NetSafe MDR employs continuous, active monitoring of all network traffic and activity. This allows for the detection of suspicious behaviors, such as Interlock attempting to modify administrative files or other unauthorized movements within the network. ‍
2. Human-Led Response: Our MDR service is powered by a team of highly experienced security analysts. These experts are not only adept at identifying sophisticated threats, but also actively and strategically respond to incidents like Interlock ensuring comprehensive containment and remediation.
3. ‍Contextual Security: NetSafe MDR goes beyond simple alerts by understanding the relationships between emerging threats and existing vulnerabilities. This contextual intelligence enables us to precisely identify activities, such as Interlock attempting to exfiltrate data. ‍
4. Quick Reaction: Leveraging advanced detection logic and AI-enhanced alerting capabilities, NetSafe MDR empowers our human-led response team to react with unprecedented speed. This rapid intervention allows us to stop threats like Interlock in their tracks.

What’s the Next Step?

If you want more information on NetSafe MDR or are considering ways to implement MDR as part of your broader security strategy, contact Net Friends. When you enroll in NetSafe MDR, you can trust that no matter how an attack begins on your network, it will be stopped with unmatched speed and thoroughness. 

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