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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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June 9, 2025

Modernising UK Cyber Regulation: Implications of the Cyber Security and Resilience Bill

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The need for security and continued cyber resilience

The UK government has made national security a key priority, and the new Cyber Security and Resilience Bill (CSRB) is a direct reflection of that focus. In introducing the Bill, Secretary of State for Science, Innovation and Technology, Peter Kyle, recognised that the UK is “desperately exposed” to cyber threats—from criminal groups to hostile nation-states that are increasingly targeting the UK's digital systems and critical infrastructure[1].

Context and timeline for the new legislation

First announced during the King’s Speech of July 2024, and elaborated in a Department for Science, Innovation and Technology (DSIT) policy statement published in April 2025, the CSRB is expected to be introduced in Parliament during the 2025-26 legislative session.

For now, organisations in the UK remain subject to the 2018 Network and Information Systems (NIS) Regulations – an EU-derived law which was drafted before today’s increasing digitisation of critical services, rise in cloud adoption and emergence of AI-powered threats.

Why modernisation is critical

Without modernisation, the Government believes UK’s infrastructure and economy risks falling behind international peers. The EU, which revised its cybersecurity regulation under the NIS2 Directive, already imposes stricter requirements on a broader set of sectors.

The urgency of the Bill is also underscored by recent high-impact incidents, including the Synnovis attack which targeted the National Health Service (NHS) suppliers and disrupted thousands of patient appointments and procedures[2]. The Government has argued that such events highlight a systemic failure to keep pace with a rapidly evolving threat landscape[3].

What the Bill aims to achieve

This Bill represents a decisive shift. According to the Government, it will modernise and future‑proof the UK’s cyber laws, extending oversight to areas where risk has grown but regulation has not kept pace[4]. While the legislation builds on previous consultations and draws lessons from international frameworks like the EU’s NIS2 directive, it also aims to tailor solutions to the UK’s unique threat environment.

Importantly, the Government is framing cybersecurity not as a barrier to growth, but as a foundation for it. The policy statement emphasises that strong digital resilience will create the stability businesses need to thrive, innovate, and invest[5]. Therefore, the goals of the Bill will not only be to enhance security but also act as an enabler to innovation and economic growth.

Recognition that AI changes cyber threats

The CSRB policy statement recognises that AI is fundamentally reshaping the threat landscape, with adversaries now leveraging AI and commercial cyber tools to exploit vulnerabilities in critical infrastructure and supply chains. Indeed, the NCSC has recently assessed that AI will almost certainly lead to “an increase in the frequency and intensity of cyber threats”[6]. Accordingly, the policy statement insists that the UK’s regulatory framework “must keep pace and provide flexibility to respond to future threats as and when they emerge”[7].

To address the threat, the Bill signals new obligations for MSPs and data centres, timely incident reporting and dynamic guidance that can be refreshed without fresh primary legislation, making it essential for firms to follow best practices.

What might change in day-to-day practice?

New organisations in scope of regulation

Under the existing Network and Information Systems (NIS) Regulations[8], the UK already supervises operators in five critical sectors—energy, transport, drinking water, health (Operators of Essential Services, OES) and digital infrastructure (Relevant Digital Service Providers, RDSPs).

The Cyber Security and Resilience Bill retains this foundation and adds Managed Service Providers (MSPs) and data centres to the scope of regulation to “better recognise the increasing reliance on digital services and the vulnerabilities posed by supply chains”[9]. It also grants the Secretary of State for Science, Innovation and Technology the power to add new sectors or sub‑sectors via secondary legislation, following consultation with Parliament and industry.

Managed service providers (MSPs)

MSPs occupy a central position within the UK’s enterprise information‑technology infrastructure. Because they remotely run or monitor clients’ systems, networks and data, they hold privileged, often continuous access to multiple environments. This foothold makes them an attractive target for malicious actors.

The Bill aims to bring MSPs in scope of regulation by making them subject to the same duties as those placed on firms that provide digital services under the 2018 NIS Regulations. By doing so, the Bill seeks to raise baseline security across thousands of customer environments and to provide regulators with better visibility of supply‑chain risk.

The proposed definition for MSPs is a service which:

  1. Is provided to another organisation
  2. Relies on the use of network and information systems to deliver the service
  3. Relates to ongoing management support, active administration and/or monitoring of AI systems, IT infrastructure, applications, and/or IT networks, including for the purpose of activities relating to cyber security.
  4. Involves a network connection and/or access to the customer’s network and information systems.

Data centres

Building on the September 2024 designation of data centres as critical national infrastructure, the CSRB will fold data infrastructure into the NIS-style regime by naming it an “relevant sector" and data centres as “essential service”[10].

About 182 colocation facilities run by 64 operators will therefore come under statutory duties to notify the regulator, maintain proportionate CAF-aligned controls and report significant incidents, regardless of who owns them or what workloads they host.

New requirements for regulated organisations

Incident reporting processes

There could be stricter timelines or broader definitions of what counts as a reportable incident. This might nudge organisations to formalise detection, triage, and escalation procedures.

The Government is proposing to introduce a new two-stage incident reporting process. This would include an initial notification which would be submitted within 24 hours of becoming aware of a significant incident, followed by a full incident report which should be submitted within 72 hours of the same.

Supply chain assurance requirements

Supply chains for the UK's most critical services are becoming increasingly complex and present new and serious vulnerabilities for cyber-attacks. The recent Synnovis ransomware attacks on the NHS[11] exemplify the danger posed by attacks against the supply chains of important services and organisations. This is concerning when reflecting on the latest Cyber Security Breaches survey conducted by DSIT, which highlights that fewer than 25% of large businesses review their supply chain risks[12].

Despite these risks, the UK’s legacy cybersecurity regulatory regime does not explicitly cover supply chain risk management. The UK instead relies on supporting and non-statutory guidance to close this gap, such as the NCSC’s Cyber Assessment Framework (CAF)[13].

The CSRB policy statement acts on this regulatory shortcoming and recognises that “a single supplier’s disruption can have far-reaching impacts on the delivery of essential or digital services”[14].

To address this, the Bill would make in-scope organisations (OES and RDPS) directly accountable for the cybersecurity of their supply chains. Secondary legislation would spell out these duties in detail, ensuring that OES and RDSPs systematically assess and mitigate third-party cyber risks.

Updated and strengthened security requirements

By placing the CAF into a firmer footing and backing it with a statutory Code of Practice, the Government is setting clearer expectations about government expectations on technical standards and methods organisations will need to follow to prove their resilience.

How Darktrace can help support affected organizations

Demonstrate resilience

Darktrace’s Self-Learning AITM continuously monitors your digital estate across cloud, network, OT, email, and endpoint to detect, investigate, and autonomously respond to emerging threats in real time. This persistent visibility and defense posture helps organizations demonstrate cyber resilience to regulators with confidence.

Streamline incident reporting and compliance

Darktrace surfaces clear alerts and automated investigation reports, complete with timeline views and root cause analysis. These insights reduce the time and complexity of regulatory incident reporting and support internal compliance workflows with auditable, AI-generated evidence.

Improve supply chain visibility

With full visibility across connected systems and third-party activity, Darktrace detects early indicators of lateral movement, account compromise, and unusual behavior stemming from vendor or partner access, reducing the risk of supply chain-originated cyber-attacks.

Ensure MSPs can meet new standards

For managed service providers, Darktrace offers native multi-tenant support and autonomous threat response that can be embedded directly into customer environments. This ensures consistent, scalable security standards across clients—helping MSPs address increasing regulatory obligations.

[related-resource]

References

[1] https://www.theguardian.com/uk-news/article/2024/jul/29/uk-desperately-exposed-to-cyber-threats-and-pandemics-says-minister

[2] https://www.england.nhs.uk/2024/06/synnovis-cyber-attack-statement-from-nhs-england/

[3] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

[4] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

[5] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

[6] https://www.ncsc.gov.uk/report/impact-ai-cyber-threat-now-2027

[7] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

[8] https://www.gov.uk/government/collections/nis-directive-and-nis-regulations-2018

[9] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

[10] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

[11] https://www.england.nhs.uk/2024/06/synnovis-cyber-attack-statement-from-nhs-england/

[12] https://www.gov.uk/government/statistics/cyber-security-breaches-survey-2025/cyber-security-breaches-survey-2025

[13] https://www.ncsc.gov.uk/collection/cyber-assessment-framework

[14] https://www.gov.uk/government/publications/cyber-security-and-resilience-bill-policy-statement/cyber-security-and-resilience-bill-policy-statement

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June 5, 2025

Unpacking ClickFix: Darktrace’s detection of a prolific social engineering tactic

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What is ClickFix and how does it work?

Amid heightened security awareness, threat actors continue to seek stealthy methods to infiltrate target networks, often finding the human end user to be the most vulnerable and easily exploited entry point.

ClickFix baiting is an exploitation of the end user, making use of social engineering techniques masquerading as error messages or routine verification processes, that can result in malicious code execution.

Since March 2024, the simplicity of this technique has drawn attention from a range of threat actors, from individual cybercriminals to Advanced Persistent Threat (APT) groups such as APT28 and MuddyWater, linked to Russia and Iran respectively, introducing security threats on a broader scale [1]. ClickFix campaigns have been observed affecting organizations in across multiple industries, including healthcare, hospitality, automotive and government [2][3].

Actors carrying out these targeted attacks typically utilize similar techniques, tools and procedures (TTPs) to gain initial access. These include spear phishing attacks, drive-by compromises, or exploiting trust in familiar online platforms, such as GitHub, to deliver malicious payloads [2][3]. Often, a hidden link within an email or malvertisements on compromised legitimate websites redirect the end user to a malicious URL [4]. These take the form of ‘Fix It’ or fake CAPTCHA prompts [4].

From there, users are misled into believing they are completing a human verification step, registering a device, or fixing a non-existent issue such as a webpage display error. As a result, they are guided through a three-step process that ultimately enables the execution of malicious PowerShell commands:

  1. Open a Windows Run dialog box [press Windows Key + R]
  2. Automatically or manually copy and paste a malicious PowerShell command into the terminal [press CTRL+V]
  3. And run the prompt [press ‘Enter’] [2]

Once the malicious PowerShell command is executed, threat actors then establish command and control (C2) communication within the targeted environment before moving laterally through the network with the intent of obtaining and stealing sensitive data [4]. Malicious payloads associated with various malware families, such as XWorm, Lumma, and AsyncRAT, are often deployed [2][3].

Attack timeline of ClickFix cyber attack

Based on investigations conducted by Darktrace’s Threat Research team in early 2025, this blog highlights Darktrace’s capability to detect ClickFix baiting activity following initial access.

Darktrace’s coverage of a ClickFix attack chain

Darktrace identified multiple ClickFix attacks across customer environments in both Europe, the Middle East, and Africa (EMEA) and the United States. The following incident details a specific attack on a customer network that occurred on April 9, 2025.

Although the initial access phase of this specific attack occurred outside Darktrace’s visibility, other affected networks showed compromise beginning with phishing emails or fake CAPTCHA prompts that led users to execute malicious PowerShell commands.

Darktrace’s visibility into the compromise began when the threat actor initiated external communication with their C2 infrastructure, with Darktrace / NETWORK detecting the use of a new PowerShell user agent, indicating an attempt at remote code execution.

Darktrace / NETWORK's detection of a device making an HTTP connection with new PowerShell user agent, indicating PowerShell abuse for C2 communications.
Figure 1: Darktrace / NETWORK's detection of a device making an HTTP connection with new PowerShell user agent, indicating PowerShell abuse for C2 communications.

Download of Malicious Files for Lateral Movement

A few minutes later, the compromised device was observed downloading a numerically named file. Numeric files like this are often intentionally nondescript and associated with malware. In this case, the file name adhered to a specific pattern, matching the regular expression: /174(\d){7}/. Further investigation into the file revealed that it contained additional malicious code designed to further exploit remote services and gather device information.

Darktrace / NETWORK's detection of a numeric file, one minute after the new PowerShell User Agent alert.
Figure 2: Darktrace / NETWORK's detection of a numeric file, one minute after the new PowerShell User Agent alert.

The file contained a script that sent system information to a specified IP address using an HTTP POST request, which also processed the response. This process was verified through packet capture (PCAP) analysis conducted by the Darktrace Threat Research team.

By analyzing the body content of the HTTP GET request, it was observed that the command converts the current time to Unix epoch time format (i.e., 9 April 2025 13:26:40 GMT), resulting in an additional numeric file observed in the URI: /1744205200.

PCAP highlighting the HTTP GET request that sends information to the specific IP, 193.36.38[.]237, which then generates another numeric file titled per the current time.
Figure 3: PCAP highlighting the HTTP GET request that sends information to the specific IP, 193.36.38[.]237, which then generates another numeric file titled per the current time.

Across Darktrace’s investigations into other customers' affected by ClickFix campaigns, both internal information discovery events and further execution of malicious code were observed.

Data Exfiltration

By following the HTTP stream in the same PCAP, the Darktrace Threat Research Team assessed the activity as indicative of data exfiltration involving system and device information to the same command-and-control (C2) endpoint, , 193.36.38[.]237. This endpoint was flagged as malicious by multiple open-source intelligence (OSINT) vendors [5].

PCAP highlighting HTTP POST connection with the numeric file per the URI /1744205200 that indicates data exfiltration to 193.36.38[.]237.
Figure 4: PCAP highlighting HTTP POST connection with the numeric file per the URI /1744205200 that indicates data exfiltration to 193.36.38[.]237.

Further analysis of Darktrace’s Advanced Search logs showed that the attacker’s malicious code scanned for internal system information, which was then sent to a C2 server via an HTTP POST request, indicating data exfiltration

Advanced Search further highlights Darktrace's observation of the HTTP POST request, with the second numeric file representing data exfiltration.
Figure 5: Advanced Search further highlights Darktrace's observation of the HTTP POST request, with the second numeric file representing data exfiltration.

Actions on objectives

Around ten minutes after the initial C2 communications, the compromised device was observed connecting to an additional rare endpoint, 188.34.195[.]44. Further analysis of this endpoint confirmed its association with ClickFix campaigns, with several OSINT vendors linking it to previously reported attacks [6].

In the final HTTP POST request made by the device, Darktrace detected a file at the URI /init1234 in the connection logs to the malicious endpoint 188.34.195[.]44, likely depicting the successful completion of the attack’s objective, automated data egress to a ClickFix C2 server.

Darktrace / NETWORK grouped together the observed indicators of compromise (IoCs) on the compromised device and triggered an Enhanced Monitoring model alert, a high-priority detection model designed to identify activity indicative of the early stages of an attack. These models are monitored and triaged 24/7 by Darktrace’s Security Operations Center (SOC) as part of the Managed Threat Detection service, ensuring customers are promptly notified of malicious activity as soon as it emerges.

Darktrace correlated the separate malicious connections that pertained to a single campaign.
Figure 6: Darktrace correlated the separate malicious connections that pertained to a single campaign.

Darktrace Autonomous Response

In the incident outlined above, Darktrace was not configured in Autonomous Response mode. As a result, while actions to block specific connections were suggested, they had to be manually implemented by the customer’s security team. Due to the speed of the attack, this need for manual intervention allowed the threat to escalate without interruption.

However, in a different example, Autonomous Response was fully enabled, allowing Darktrace to immediately block connections to the malicious endpoint (138.199.156[.]22) just one second after the initial connection in which a numerically named file was downloaded [7].

Darktrace Autonomous Response blocked connections to a suspicious endpoint following the observation of the numeric file download.
Figure 7: Darktrace Autonomous Response blocked connections to a suspicious endpoint following the observation of the numeric file download.

This customer was also subscribed to our Managed Detection and Response service, Darktrace’s SOC extended a ‘Quarantine Device’ action that had already been autonomously applied in order to buy their security team additional time for remediation.

Autonomous Response blocked connections to malicious endpoints, including 138.199.156[.]22, 185.250.151[.]155, and rkuagqnmnypetvf[.]top, and also quarantined the affected device. These actions were later manually reinforced by the Darktrace SOC.
Figure 8: Autonomous Response blocked connections to malicious endpoints, including 138.199.156[.]22, 185.250.151[.]155, and rkuagqnmnypetvf[.]top, and also quarantined the affected device. These actions were later manually reinforced by the Darktrace SOC.

Conclusion

ClickFix baiting is a widely used tactic in which threat actors exploit human error to bypass security defenses. By tricking end point users into performing seemingly harmless, everyday actions, attackers gain initial access to systems where they can access and exfiltrate sensitive data.

Darktrace’s anomaly-based approach to threat detection identifies early indicators of targeted attacks without relying on prior knowledge or IoCs. By continuously learning each device’s unique pattern of life, Darktrace detects subtle deviations that may signal a compromise. In this case, Darktrace's Autonomous Response, when operating in a fully autonomous mode, was able to swiftly contain the threat before it could progress further along the attack lifecycle.

Credit to Keanna Grelicha (Cyber Analyst) and Jennifer Beckett (Cyber Analyst)

Appendices

NETWORK Models

  • Device / New PowerShell User Agent
  • Anomalous Connection / New User Agent to IP Without Hostname
  • Anomalous Connection / Posting HTTP to IP Without Hostname
  • Anomalous Connection / Powershell to Rare External
  • Device / Suspicious Domain
  • Device / New User Agent and New IP
  • Anomalous File / New User Agent Followed By Numeric File Download (Enhanced Monitoring Model)
  • Device / Initial Attack Chain Activity (Enhanced Monitoring Model)

Autonomous Response Models

  • Antigena / Network::Significant Anomaly::Antigena Significant Anomaly from Client Block
  • Antigena / Network::Significant Anomaly::Antigena Enhanced Monitoring from Client Block
  • Antigena / Network::External Threat::Antigena File then New Outbound Block
  • Antigena / Network::External Threat::Antigena Suspicious File Block
  • Antigena / Network::Significant Anomaly::Antigena Alerts Over Time Block
  • Antigena / Network::External Threat::Antigena Suspicious File Block

IoC - Type - Description + Confidence

·       141.193.213[.]11 – IP address – Possible C2 Infrastructure

·       141.193.213[.]10 – IP address – Possible C2 Infrastructure

·       64.94.84[.]217 – IP address – Possible C2 Infrastructure

·       138.199.156[.]22 – IP address – C2 server

·       94.181.229[.]250 – IP address – Possible C2 Infrastructure

·       216.245.184[.]181 – IP address – Possible C2 Infrastructure

·       212.237.217[.]182 – IP address – Possible C2 Infrastructure

·       168.119.96[.]41 – IP address – Possible C2 Infrastructure

·       193.36.38[.]237 – IP address – C2 server

·       188.34.195[.]44 – IP address – C2 server

·       205.196.186[.]70 – IP address – Possible C2 Infrastructure

·       rkuagqnmnypetvf[.]top – Hostname – C2 server

·       shorturl[.]at/UB6E6 – Hostname – Possible C2 Infrastructure

·       tlgrm-redirect[.]icu – Hostname – Possible C2 Infrastructure

·       diagnostics.medgenome[.]com – Hostname – Compromised Website

·       /1741714208 – URI – Possible malicious file

·       /1741718928 – URI – Possible malicious file

·       /1743871488 – URI – Possible malicious file

·       /1741200416 – URI – Possible malicious file

·       /1741356624 – URI – Possible malicious file

·       /ttt – URI – Possible malicious file

·       /1741965536 – URI – Possible malicious file

·       /1.txt – URI – Possible malicious file

·       /1744205184 – URI – Possible malicious file

·       /1744139920 – URI – Possible malicious file

·       /1744134352 – URI – Possible malicious file

·       /1744125600 – URI – Possible malicious file

·       /1[.]php?s=527 – URI – Possible malicious file

·       34ff2f72c191434ce5f20ebc1a7e823794ac69bba9df70721829d66e7196b044 – SHA-256 Hash – Possible malicious file

·       10a5eab3eef36e75bd3139fe3a3c760f54be33e3 – SHA-1 Hash – Possible malicious file

MITRE ATT&CK Mapping

Tactic – Technique – Sub-Technique  

Spearphishing Link - INITIAL ACCESS - T1566.002 - T1566

Drive-by Compromise - INITIAL ACCESS - T1189

PowerShell - EXECUTION - T1059.001 - T1059

Exploitation of Remote Services - LATERAL MOVEMENT - T1210

Web Protocols - COMMAND AND CONTROL - T1071.001 - T1071

Automated Exfiltration - EXFILTRATION - T1020 - T1020.001

References

[1] https://www.logpoint.com/en/blog/emerging-threats/clickfix-another-deceptive-social-engineering-technique/

[2] https://www.proofpoint.com/us/blog/threat-insight/security-brief-clickfix-social-engineering-technique-floods-threat-landscape

[3] https://cyberresilience.com/threatonomics/understanding-the-clickfix-attack/

[4] https://www.group-ib.com/blog/clickfix-the-social-engineering-technique-hackers-use-to-manipulate-victims/

[5] https://www.virustotal.com/gui/ip-address/193.36.38.237/detection

[6] https://www.virustotal.com/gui/ip-address/188.34.195.44/community

[7] https://www.virustotal.com/gui/ip-address/138.199.156.22/detection

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About the author
Keanna Grelicha
Cyber Analyst
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