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February 6, 2025

RansomHub Revisited: New Front-Runner in the Ransomware-as-a-Service Marketplace

Discover how RansomHub is rising in the ransomware landscape, using tools like Atera and Splashtop, reconnaissance tactics, and double extortion techniques.
Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Maria Geronikolou
Cyber Analyst
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06
Feb 2025

In a previous Inside the SOC blog, Darktrace investigated RansomHub and its growing impact on the threat landscape due to its use by the ShadowSyndicate threat group. Here, RansomHub is revisited with new insights on this ransomware-as-a-service (RaaS) platform that has rapidly gained traction among threat actors of late.

In recent months, Darktrace’s Threat Research team has noted a significant uptick in potential compromises affecting the fleet, indicating that RansomHub is becoming a preferred tool for cybercriminals.  This article delves into the increasing adoption of RansomHub, the tactics, techniques, and procedures (TTPs) employed by its affiliates, and the broader implications for organizations striving to protect their systems.

RansomHub overview & background

One notable threat group to have transitioned from ALPHV (BlackCat)-aligned operations to RansomHub-aligned operations is ScatteredSpider [1]. The adoption of RansomHub by ScatteredSpider and other threat actors suggests a possible power shift among threat groups, given the increasing number of cybercriminals adopting it, including those who previously relied on ALPHV’s malware code [2].

ALPHV was a RaaS strain used by cybercriminals to breach Change Healthcare in February 2024 [2]. However, there are claims that the ransom payment never reached the affiliate using ALPHV, leading to a loss of trust in the RaaS. Around the same time, Operation Cronos resulted in the shutdown of LockBit and the abandonment of its affiliates [2]. Consequently, RansomHub emerged as a prominent RaaS successor.

RansomHub targets

The RansomHub ransomware group has been observed targeting various sectors, including critical infrastructure, financial and government services, and the healthcare sector [4]. They use ransomware variants rewritten in GoLang to target both Windows and Linux systems [5]. RansomHub is known for employing double extortion attacks, encrypting data using “Curve25519” encryption [6].

RansomHub tactics and techniques

The attackers leverage phishing attacks and social engineering techniques to lure their victims. Once access is gained, they use sophisticated tools to maintain control over compromised networks and exploit vulnerabilities in systems like Windows, Linux, ESXI, and NAS.

In more recent RansomHub attacks, tools such as Atera and Splashtop have been used to facilitate remote access, while NetScan has been employed to discover and retrieve information about network devices [7].

External researchers have observed that RansomHub uses several legitimate tools, or a tactic known as Living-off-the-Land (LOTL), to carry out their attacks. These tools include:

  • SecretServerSecretStealer: A PowerShell script that allows for the decryption of passwords [1].
  • Ngrok: A legitimate reverse proxy tool that creates a secure tunnel to servers located behind firewalls, used by the group for lateral movement and data exfiltration.
  • Remmina: An open-source remote desktop client for POSIX-based operating systems, enabling threat actors to access remote services [1].

By using these legitimate tools instead of traditional malware, RansomHub can avoid detection and maintain a lower profile during their operations.

Darktrace’s Coverage of RansomHub

Darktrace’s Security Operations Center (SOC) detected several notable cases of likely RansomHub activity across the customer base in recent months. In all instances, threat actors performed network scanning and brute force activities.

During the investigation of a confirmed RansomHub attack in January 2025, the Darktrace Threat Research team identified multiple authentication attempts as attackers tried to retrieve valid credentials. It is plausible that the attackers gained entry to customer environments through their Remote Desktop (RD) web server. Following this, various RDP connections were made to pivot to other devices within the network.

The common element among the cases investigated was that, in most instances, devices were seen performing outgoing connections to splashtop[.]com, a remote access and support software service, after the scanning activity had occurred. On one customer network, following this activity, the same device was seen connecting to the domain agent-api[.]atera[.]com and IP 20.37.139[.]187, which are seemingly linked to Atera, a Remote Monitoring and Management (RMM) tool.

Model Alert Log of an affected device making connections to *atera[.]com.
Figure 1: Model Alert Log of an affected device making connections to *atera[.]com.

In a separate case, a Darktrace observed a device attempting to perform SMB scanning activity, trying to connect to multiple internal devices over port 445. Cyber AI Analyst was able to detect and correlate these individual connections into a single reconnaissance incident.

Similar connections to Remote Monitoring and Management (RMM) tools were also detected in a different customer environment, as alerted by Darktrace’s SOC. Unusual connections to Splashtop and Atera were made from the alerted device. Following this, the same device was observed sending a large volume of data over SSH Rclone to a rare external endpoint on the unusual port 448, triggered multiple models in Darktrace / NETWORK.

Advanced Search graph demonstrating the rarity of the  external IP 38.244.145[.]85  used for data exfiltration.
Figure 2: Advanced Search graph demonstrating the rarity of the  external IP 38.244.145[.]85  used for data exfiltration.
Model Alert Log displaying information related to the suspicious IP, including the port used and its rarity for the network.
Figure 3: Model Alert Log displaying information related to the suspicious IP, including the port used and its rarity for the network.

In the cases observed, data exfiltration occurred alongside the encryption of files likely indicating double extortion tactics. In September 2024, the Darktrace’s Threat Research team identified a 6-digit alphanumeric additional extension similar to “.293ac3”. This case was closely linked to a RansomHub attack, which was also analyzed in a different blog post by Darktrace [8].

Event Log displaying the extension “.293ac3” being appended to encrypted files on an affected customer network.
Figure 4: Event Log displaying the extension “.293ac3” being appended to encrypted files on an affected customer network.

Conclusion

RansomHub exemplifies the evolving RaaS ecosystem, where threat actors capitalize on ready-made platforms to launch sophisticated attacks with ease. The activities observed highlight its growing popularity among cybercriminals. The analysis showed that the different attacks investigated followed a similar pattern of activity.

First, attackers perform reconnaissance activities, including widespread scanning from multiple devices and reverse DNS sweeps. They then use high-privileged credentials to pivot among devices and establish remote connections using RMM tools such as Atera. A common element among most attacks that reached the data encryption stage is the use of a 6-digit alphanumeric extension.

In all cases, Darktrace alerted on the unusual activities observed, creating not only model alerts but also Cyber AI Analyst incidents. Both Darktrace Security Operations Support and Darktrace Managed Threat Detection services provided 24/7 assistance to clients affected by RansomHub. The analyst team continued investigating these incidents, gathering data and IoCs seen in the RansomHub incidents, providing valuable insight and guidance throughout the process.

As RansomHub continues to gain traction, it serves as a stark reminder of the need for robust cybersecurity measures, proactive threat intelligence, and continued vigilance.

Credit to Maria Geronikolou (Cyber Analyst) and Nahisha Nobregas (Senior Cyber Analyst)

[related-resource]

Appendices

Darktrace Model Detections

Network Reconnaissance

o   Device / Network Scan

o   Device / ICMP Address Scan

o   Device / RDP Scan

o   Device / Anomalous LDAP Root Searches

o   Anomalous Connection / SMB Enumeration

o   Device / Spike in LDAP Activity

o   Device / Suspicious Network Scan Activity

Lateral Movement

o   Device / Multiple Lateral Movement Model Alerts

o   Device / Increase in New RPC Services

o   Device / New or Uncommon WMI Activity

o   Device / Possible SMB/NTLM Brute Force

o   Device / SMB Session Brute Force (Non-Admin)

o   Device / Anomalous NTLM Brute Force

o   Compliance / Default Credential Usage

o   Compliance / Outgoing NTLM Request from DC

C2 Activity

o   Anomalous Server Activity / Outgoing from Server

o   Anomalous Connection / Multiple Connections to New External TCP Port

o   Unusual Activity / Unusual External Activity

o   Compliance / Remote Management Tool On Server

Data Exfiltration

o   Unusual Activity / Enhanced Unusual External Data Transfer

o   Anomalous Connection / Outbound SSH to Unusual Port

o   Compliance / SSH to Rare External Destination

o   Unusual Activity / Unusual External Data to New Endpoint

o   Unusual Activity / Unusual External Data Transfer

o   Attack Path Modelling / Unusual Data Transfer on Critical Attack Path

o   Compliance / Possible Unencrypted Password File On Server

Autonomous Response Models

-       Antigena / Network / Significant Anomaly / Antigena Significant Anomaly from Client Block

-       Antigena/Network/Insider Threat/Antigena SMB Enumeration Block

-       Antigena / Network / Significant Anomaly / Antigena Alerts Over Time Block

-       Antigena / Network / Significant Anomaly / Antigena Controlled and Model Alert

List of Indicators of Compromise (IoCs)

o   38.244.145[.]85

o   20.37.139[.]187 agent-api.atera[.]com

o   108.157.150[.]120 ps.atera[.]com

o   st-v3-univ-srs-win-3720[.]api[.]splashtop[.]com

MITRE ATT&CK Mapping

  • RECONNAISSANCE T1592.004
  • RECONNAISSANCE T1595.002
  • DISCOVERY T1046
  • DISCOVERY T1083
  • DISCOVERY T1135
  • DISCOVERY T1018
  • INITIAL ACCESS T1190
  • CREDENTIAL ACCESS T1110
  • LATERAL MOVEMENT T1210
  • COMMAND AND CONTROL T1001
  • EXFILTRATION T1041
  • EXFILTRATION T1567.002

References

[1] https://www.guidepointsecurity.com/blog/worldwide-web-an-analysis-of-tactics-and-techniques-attributed-to-scattered-spider/

[2] https://www.theregister.com/2024/07/16/scattered_spider_ransom/

[3] https://krebsonsecurity.com/2024/03/blackcat-ransomware-group-implodes-after-apparent-22m-ransom-payment-by-change-healthcare/

[4] https://thehackernews.com/2024/09/ransomhub-ransomware-group-targets-210.html

[5] https://www.trendmicro.com/vinfo/us/security/news/ransomware-spotlight/ransomware-spotlight-ransomhub

[6] https://areteir.com/article/malware-spotlight-ransomhub-ransomware/
[7] https://www.security.com/threat-intelligence/ransomhub-knight-ransomware

[8] https://darktrace.com/blog/ransomhub-ransomware-darktraces-investigation-of-the-newest-tool-in-shadowsyndicates-arsenal

Get the latest insights on emerging cyber threats

This report explores the latest trends shaping the cybersecurity landscape and what defenders need to know in 2025

Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Maria Geronikolou
Cyber Analyst

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September 26, 2025

One-Person Security Team, Enterprise-Wide Protection: A Utility Company’s Darktrace Success Story

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A critical mission: Securing public utility systems

This company manages essential utility infrastructure across more than 100 distributed sites, resulting in a wide attack surface spanning both information technology (IT) and operational technology (OT). With attacks on critical infrastructure rising, the company wanted to strengthen defenses.

The limits of traditional tools

The existing mix of conventional tools for visibility and security monitoring posed numerous limitations:

  • Fragmented tools required switching between dashboards to piece together insights
  • Multiple tools were required to both identify and take action on potential incidents
  • Integration between IT, OT, cloud and email required heavy manual effort
  • Existing cybersecurity investments were failing to deliver favorable ROI

A security team of one

For the company’s one-person security team and Vice President of IT, juggling multiple tools and switching between platforms were drains on his time and impacted threat detection and response times. “If an unknown actor attempts to connect to our networks, I need to know immediately and have the ability to stop them before they can do damage.”

Unified, AI-driven defense with Darktrace

The company wanted to unify IT and OT security, reduce manual workload and deliver actionable intelligence in real time. “Darktrace offered the visibility and autonomous capabilities we needed for a proactive defense, including the ability to both see incidents and take action through a single-pane-of-glass.”

Today, the company is using the Darktrace ActiveAI Security Platform™ as the cornerstone of its defense strategy, including:

Real-time protection without the overhead

When compared to a security operations center, the VP said Darktrace is faster, more efficient and more accurate – delivering holistic protection without the high cost or risk of human error.

Darktrace’s Autonomous Response has been a game changer for a shop our size. It stops attacks in real time, before they can move laterally. As a team of one, I can adjust Darktrace’s autonomous actions, ensuring the AI automatically takes stronger actions during off hours to contain threats.”

A single platform for holistic visibility and resilience

Initially licensed under an OT-only pricing model, the company quickly recognized the broader value of Darktrace Self-Learning AI – extending deployment across its IT, cloud, email and endpoint environments and consolidating multiple tools. This holistic visibility is also helping the company to meet ISO and SEC compliance requirements.

A rapid, guided and streamlined deployment

The VP described the Darktrace rollout as smooth and highly collaborative, noting that Darktrace, “Held our hand throughout the process and was genuinely interested in making sure our experience with the platform and the company was top notch.” Despite the complexity of managing multi-connectivity for 100 sites, rollout took less than one week, guided by a clear plan from the Darktrace implementation team.

From barriers to breakthroughs

A seamless security ecosystem

With Darktrace, the company now operates a seamless, AI-driven security ecosystem that combines deep threat validation, intuitive user experience, and a single pane of glass for holistic cyber defense. What began as an OT-focused deployment has grown into a platform that unifies IT, OT, cloud, email and endpoint visibility, delivering comprehensive protection without the overhead of managing multiple tools.

From false positives to real-time, autonomous precision

Since using Darktrace, the company’s false positives have decreased to single digits per day. Within three months, Darktrace conducted 1,470 total investigations, resolving 92% of those autonomously. And Darktrace consistently catches threats that other tools miss:

  • When a remote call center agent landed on a malware-laden site using their company device, the company’s endpoint solution failed to catch it. But Darktrace / ENDPOINT detected the malicious traffic in real time, immediately cutting the connection and blocking the machine from the home network – stopping the attack before it could spread.
  • Darktrace / EMAIL has consistently flagged suspicious messages other tools missed, including credential harvesters or malware disguised as legitimate emails. “Occasionally users request the release of a legitimate email, whether it’s a blocked link or a message diverted to junk. But 10% of those messages could have caused real harm,” said the VP. “And because Darktrace AI is always learning and adapting, it will identify similar legitimate emails in the future, reducing false positives. That tradeoff is well worth it.”

Time saved, confidence gained

For the VP, one of the biggest benefits is time. In less than one month, Darktrace saved the company 264 analyst hours spent on investigations, only escalating 8% of suspected threats for further review. And with Darktrace’s unified dashboard and real-time monitoring, the VP said, “I no longer have to spend time verifying each security tool is working because I can see everything in one location. And, if there is an issue, Darktrace will let me know. That gives me confidence to let the system handle threats while I focus on other priorities.”

Strengthening OT without complexity

The VP said Darktrace / OT has become one of the most valuable aspects of the deployment. Darktrace / OT provides visibility into firmware levels, PLC communications and unusual device interactions that even dedicated OT tools miss. And using Darktrace, the company can segment OT networks securely while still monitoring them through a single interface, strengthening resilience without adding complexity.

Turning cybersecurity into a business catalyst

By reducing tool sprawl, automating responses, and adapting to the unique rhythms of the organization, Darktrace has transformed the company’s cybersecurity from a constant worry into a reliable foundation.

For us, cybersecurity isn’t just about blocking threats, it’s about building resilience that frees us to focus on growth and innovation. With Darktrace as a trusted partner, we’re no longer stuck reacting to problems; we’re shaping a future where security is a catalyst, not a constraint.”
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September 25, 2025

Announcing Unified Real-Time CDR and Automated Investigations to Transform Cloud Security Operations

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Fragmented Tools are Failing SOC Teams in the Cloud Era

The cloud has transformed how businesses operate, reshaping everything from infrastructure to application delivery. But cloud security has not kept pace. Most tools still rely on traditional models of logging, policy enforcement, and posture management; approaches that provide surface-level visibility but lack the depth to detect or investigate active attacks.

Meanwhile, attackers are exploiting vulnerabilities, delivering cloud-native exploits, and moving laterally in ways that posture management alone cannot catch fast enough. Critical evidence is often missed, and alerts lack the forensic depth SOC analysts need to separate noise from true risk. As a result, organizations remain exposed: research shows that nearly nine in ten organizations have suffered a critical cloud breach despite investing in existing security tools [1].

SOC teams are left buried in alerts without actionable context, while ephemeral workloads like containers and serverless functions vanish before evidence can be preserved. Point tools for logging or forensics only add complexity, with 82% of organizations using multiple platforms to investigate cloud incidents [2].

The result is a broken security model: posture tools surface risks but don’t connect them to active attacker behaviors, while investigation tools are too slow and fragmented to provide timely clarity. Security teams are left reactive, juggling multiple point solutions and still missing critical signals. What’s needed is a unified approach that combines real-time detection and response for active threats with automated investigation and cloud posture management in a single workflow.

Just as security teams once had to evolve beyond basic firewalls and antivirus into network and endpoint detection, response, and forensics, cloud security now requires its own next era: one that unifies detection, response, and investigation at the speed and scale of the cloud.

A Powerful Combination: Real-Time CDR + Automated Cloud Forensics

Darktrace / CLOUD now uniquely unites detection, investigation, and response into one workflow, powered by Self-Learning AI. This means every alert, from any tool in your stack, can instantly become actionable evidence and a complete investigation in minutes.

With this release, Darktrace / CLOUD delivers a more holistic approach to cloud defense, uniting real-time detection, response, and investigation with proactive risk reduction. The result is a single solution that helps security teams stay ahead of attackers while reducing complexity and blind spots.

  • Automated Cloud Forensic Investigations: Instantly capture and analyze volatile evidence from cloud assets, reducing investigation times from days to minutes and eliminating blind spots
  • Enhanced Cloud-Native Threat Detection: Detect advanced attacker behaviors such as lateral movement, privilege escalation, and command-and-control in real time
  • Enhanced Live Cloud Topology Mapping: Gain continuous insight into cloud environments, including ephemeral workloads, with live topology views that simplify investigations and expose anomalous activity
  • Agentless Scanning for Proactive Risk Reduction: Continuously monitor for misconfigurations, vulnerabilities, and risky exposures to reduce attack surface and stop threats before they escalate.

Automated Cloud Forensic Investigations

Darktrace / CLOUD now includes capabilities introduced with Darktrace / Forensic Acquisition & Investigation, triggering automated forensic acquisition the moment a threat is detected. This ensures ephemeral evidence, from disks and memory to containers and serverless workloads can be preserved instantly and analyzed in minutes, not days. The integration unites detection, response, and forensic investigation in a way that eliminates blind spots and reduces manual effort.

Figure 1: Easily view Forensic Investigation of a cloud resource within the Darktrace / CLOUD architecture map

Enhanced Cloud-Native Threat Detection

Darktrace / CLOUD strengthens its real-time behavioral detection to expose early attacker behaviors that logs alone cannot reveal. Enhanced cloud-native detection capabilities include:

• Reconnaissance & Discovery – Detects enumeration and probing activity post-compromise.

• Privilege Escalation via Role Assumption – Identifies suspicious attempts to gain elevated access.

• Malicious Compute Resource Usage – Flags threats such as crypto mining or spam operations.

These enhancements ensure active attacks are detected earlier, before adversaries can escalate or move laterally through cloud environments.

Figure 2: Cyber AI Analyst summary of anomalous behavior for privilege escalation and establishing persistence.

Enhanced Live Cloud Topology Mapping

New enhancements to live topology provide real-time mapping of cloud environments, attacker movement, and anomalous behavior. This dynamic visibility helps SOC teams quickly understand complex environments, trace attack paths, and prioritize response. By integrating with Darktrace / Proactive Exposure Management (PEM), these insights extend beyond the cloud, offering a unified view of risks across networks, endpoints, SaaS, and identity — giving teams the context needed to act with confidence.

Figure 3: Enhanced live topology maps unify visibility across architectures, identities, network connections and more.

Agentless Scanning for Proactive Risk Reduction

Darktrace / CLOUD now introduces agentless scanning to uncover malware and vulnerabilities in cloud assets without impacting performance. This lightweight, non-disruptive approach provides deep visibility into cloud workloads and surfaces risks before attackers can exploit them. By continuously monitoring for misconfigurations and exposures, the solution strengthens posture management and reduces attack surface across hybrid and multi-cloud environments.

Figure 4: Agentless scanning of cloud assets reveals vulnerabilities, which are prioritized by severity.

Together, these capabilities move cloud security operations from reactive to proactive, empowering security teams to detect novel threats in real time, reduce exposures before they are exploited, and accelerate investigations with forensic depth. The result is faster triage, shorter MTTR, and reduced business risk — all delivered in a single, AI-native solution built for hybrid and multi-cloud environments.

Accelerating the Evolution of Cloud Security

Cloud security has long been fragmented, forcing teams to stitch together posture tools, log-based monitoring, and external forensics to get even partial coverage. With this release, Darktrace / CLOUD delivers a holistic, unified approach that covers every stage of the cloud lifecycle, from proactive posture management and risk identification to real-time detection, to automated investigation and response.

By bringing these capabilities together in a single AI-native solution, Darktrace is advancing cloud security beyond incremental change and setting a new standard for how organizations protect their hybrid and multi-cloud environments.

With Darktrace / CLOUD, security teams finally gain end-to-end visibility, response, and investigation at the speed of the cloud, transforming cloud defense from fragmented and reactive to unified and proactive.

[related-resource]

Sources: [1], [2] Darktrace Report: Organizations Require a New Approach to Handle Investigations in the Cloud

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About the author
Adam Stevens
Senior Director of Product, Cloud | Darktrace
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