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April 7, 2021

Uncovering a Cryptocurrency Farm | Crypto-Mining Malware

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07
Apr 2021
Uncover the secrets of a cryptocurrency farm hidden in a warehouse. Learn about the rise of crypto-mining and its impact on the global cyber-threat landscape.

Cryptocurrencies are hitting the headlines every week and quickly becoming accepted as a mainstream investment and method of payment. Across the world, cyber-criminals are leveraging data centers called crypto-mining ‘farms’ to profit from this trend, from China to Iceland, Iran, and even a cardboard box in an empty warehouse.

How does cryptocurrency mining work?

Cryptocurrencies are decentralized digital currencies. Unlike traditional currencies, which can be issued at any time by central banks, cryptocurrency is not controlled by any centralized authority. Instead, it relies on a blockchain, which functions as a digital ledger of transactions, organized and maintained by a peer-to-peer network.

Miners create and secure cryptocurrency by solving cryptographic algorithms. Rather than hammers and chisels, crypto-miners use specialized computers with GPUs or ASICs to validate transactions as quickly as possible, earning cryptocurrency in the process.

Crypto-mining farms in 2021: Reaping the early harvest

Crypto-mining takes up an enormous amount of energy. An analysis by the University of Cambridge estimates that generating Bitcoin consumes as much, if not more, energy than entire countries. For instance, Bitcoin uses approximately 137.9 terawatt hours per year, compared to Ukraine, which uses only 128.8 in the same period. Bitcoin is just one of many cryptocurrencies, alongside Monero and Dogecoin, so the total energy consumed by all cryptocurrencies is far higher.

Given that high-powered mining computers require so much processing power, crypto-mining is lucrative in countries with relatively cheap electricity. However, the energy needed can lead to serious consequences – even shutting down entire cities. In Iran, the outdated energy grid has struggled to provide for cryptocurrency farms, resulting in city-wide blackouts.

While some of these crypto-farms are legal, illegal crypto-miners are also straining Iran’s energy supplies. Illegal crypto-mining is popular in Iran partly because Iranian currency is volatile and subject to inflation, whereas cryptocurrency is (for the moment) immune to both inflationary monetary policy and U.S. sanctions. When used for illegal purposes, cryptocurrency farming can lead to network outages and serious financial harm.

Crypto-mining malware in corporate networks

Crypto-mining malware has the ability to hamper and even crash an organization’s digital environment, if unstopped. Cyber AI has discovered and thwarted hundreds of attacks where devices are infected with crypto-mining malware, including:

  • a server in charge of opening and closing a biometric door;
  • a spectrometer, a medical IoT device which uses wavelengths of light to analyze materials;
  • 12 servers hidden under the floorboards of an Italian bank.

In one instance last year, Darktrace detected anomalous crypto-mining activity on a corporate system. Upon investigation, the organization in question traced the anomalous activity to one of their warehouses, where they found what appeared to be unassuming cardboard boxes sitting on a shelf. Opening these boxes revealed a cryptocurrency farm in disguise, running off the company’s network power.

Figure 1: The unassuming cardboard boxes

Figure 2: The cryptocurrency farm

Figure 3: The threat actors created a stealthy cryptocurrency mining rig with GPUs, running off the company’s network power

Had it remained undiscovered, the crypto-mining farm would have led to financial losses for the client and disruption to business workings. Mining rigs also generate a lot of heat and could have easily caused a fire in the warehouse.

This case demonstrates the covert methods opportunistic individuals may take to hijack corporate infrastructure with crypto-mining malware, as well as the need for a security tool which covers the entire digital estate and detects any new or unusual events. Darktrace’s machine learning flagged the connections being made from the warehouse boxes as highly anomalous, leading to this unexpected discovery.

In organizations with Darktrace RESPOND active, any anomalous crypto-mining devices would be blocked from communicating with the relevant external endpoints, effectively inhibiting mining activity. RESPOND can also enforce the normal ‘pattern of life’ across the digital environment, preventing malicious behavior while allowing normal business activities to continue. As bad actors continue to proliferate and hackers devise new ways to deploy crypto-mining malware, Darktrace’s full visibility and Autonomous Response in every part of the digital environment is more important than ever.

Thanks to Darktrace analyst Chloe Phillips for her insights.

Darktrace model detections:

  • Compliance / Crypto Currency Mining Activity
  • Compromise / High Priority Crypto Currency Mining
  • Compromise / Monero Mining
  • Anomalous Connection / Rare External SSL Self-Signed
  • Compromise / HTTP Beaconing to Rare Destination
  • Compromise / POS and Beacon to Rare External
  • Compromise / Slow Beaconing Activity to External Rare
  • Compromise / SSL Beaconing to Rare Destination
  • Compromise / Sustained TCP Beaconing Activity to Rare Endpoint
  • Anomalous Connection / Multiple Failed Connections to Rare Destination
  • Compromise / Sustained SSL or HTTP Increase
  • Anomalous Connection / Connection to New TCP Port
  • Anomalous Connection / Connection to New UDP Port
  • Compromise / Multiple UDP Connections to Rare External Hosts
  • Compromise / SSL or HTTP Beacon
  • Compromise / Quick and Regular HTTP Beaconing
  • Device / Suspicious domains
  • Compromise / Suspicious Beacons to Rare PHP Endpoint
  • Anomalous File / Script from Rare
  • Anomalous Connection / New failed External Windows Connection
  • Device / New Failed External Connection
  • Anomalous Connection / POST to PHP on New External Host
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.
Author
Justin Fier
SVP, Red Team Operations

Justin is one of the US’s leading cyber intelligence experts, and holds the position of SVP, Red Team Operations at Darktrace. His insights on cyber security and artificial intelligence have been widely reported in leading media outlets, including the Wall Street Journal, CNN, The Washington Post, and VICELAND. With over 10 years’ experience in cyber defense, Justin has supported various elements in the US intelligence community, holding mission-critical security roles with Lockheed Martin, Northrop Grumman Mission Systems and Abraxas. Justin is also a highly-skilled technical specialist, and works with Darktrace’s strategic global customers on threat analysis, defensive cyber operations, protecting IoT, and machine learning.

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March 21, 2025

Cyberhaven Supply Chain Attack: Exploiting Browser Extensions

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The evolution of supply chain attacks

Supply chain attacks are becoming increasingly sophisticated. As network defenses improve, threat actors continuously adapt and refine their tactics, techniques, and procedures (TTPs) to achieve their goals. In recent years, this has led to a rise in the exploitation of trusted services and software, including legitimate browser extensions. Exploitation of these extensions can provide adversaries with a stealthy means to infiltrate target networks and access high-value accounts undetected.

A notable example of this trend was the compromise of the Cyberhaven Chrome extension at the end of 2024. This incident appeared to be part of a broader campaign targeting multiple Chrome browser extensions, highlighting the evolving nature of supply chain attacks [1].

What is Cyberhaven?

Cyberhaven, a US-based data security organization, experienced a security breach on December 24, 2024, when a phishing attack reportedly compromised one of their employee's credentials [2]. This allowed attackers to publish a malicious version of the Cyberhaven Chrome extension, which exfiltrated cookies and authenticated sessions from targeted websites. The malicious extension was active from December 25 to December 26 – a time when most businesses and employees were out of office and enjoying the festive period, a fact not lost on threat actors. The attackers, likely a well-organized and financially motivated group, compromised more than 30 additional Chrome extensions, affecting more than 2.6 million users [3]. They used sophisticated phishing techniques to authorize malicious OAuth applications, bypassing traditional security measures and exploiting vulnerabilities in OAuth authorizations. The primary motive appeared to be financial gain, targeting high-value platforms like social media advertising and AI services [4].

In late December 2024, multiple Darktrace customers were compromised via the Cyberhaven Chrome extension; this blog will primarily focus on Darktrace / NETWORK detections from one affected customer.

Darktrace’s coverage of Cyberhaven compromises

On December 26, 2024, Darktrace identified a series of suspicious activities across multiple customer environments, uncovering a structured attack sequence that progressed from initial intrusion to privilege escalation and data exfiltration. The attack was distributed through a malicious update to the Cyberhaven Chrome extension [2]. The malicious update established a foothold in customer environments almost immediately, leading to further anomalies.

As with other Chrome browser extensions, Cyberhaven Chrome extensions were updated automatically with no user interaction required. However, in this instance, the automatic update included a malicious version which was deployed to customer environments. This almost immediately introduced unauthorized activity, allowing attackers to establish a foothold in customer networks. The update allowed attackers to execute their objectives in the background, undetected by traditional security tools that rely on known indicators of compromise (IoCS) rather than identifying anomalies.

While multiple customer devices were seen connecting to cyberhaven[.]io, a legitimate Cyberhaven domain, Darktrace detected persistent beaconing behavior to cyberhavenext[.]pro, which appeared to be attempting to masquerade as another legitimate Cyberhaven domain. Darktrace recognized this activity as unusual, triggering several model alerts in Darktrace / NETWORK to highlight the persistent outbound connections to the suspicious domain.

Further analysis of external connectivity patterns indicated  an increase in anomalous HTTP requests alongside this beaconing activity. Multiple open-source intelligence (OSINT) sources also suggest that the cyberhavenext[.]pro endpoint is associated with malicious activities [5].

Darktrace / NETWORK’s detection of beaconing activity to cyberhavenext[.]pro
Figure 1: Darktrace / NETWORK’s detection of beaconing activity to cyberhavenext[.]pro

Analysis using Darktrace’s Advanced Search revealed that some of these connections were directed to the suspicious external IP address 149.28.124[.]84. Further investigation confirmed that the IP correlated with two SSL hostnames, including the malicious cyberhavenext[.]pro, further reinforcing its connection to the attack infrastructure.

Darktrace Advanced Search analysis showing the IP address 149.28.124[.]84 correlating to two SSL hostnames, one of which is cyberhavenext[.]pro.
Figure 2: Darktrace Advanced Search analysis showing the IP address 149.28.124[.]84 correlating to two SSL hostnames, one of which is cyberhavenext[.]pro.

Between December 23 and December 27, Darktrace observed sustained beaconing-like activity from affected devices on the customer’s network.

Darktrace’s detection of beaconing activities from a customer device to the endpoint 149.28.124[.]84 between December 23 and December 27.
Figure 3: Darktrace’s detection of beaconing activities from a customer device to the endpoint 149.28.124[.]84 between December 23 and December 27.

Darktrace observed 27 unique devices connecting to the malicious command-and-control (C2) infrastructure as far back as December 3. While most connections were brief, they represented an entry point for malicious activity. Over a two-day period, two devices transmitted 5.57 GiB of incoming data and 859.37 MiB of outgoing data, generating over 3 million log events across SSL, HTTP, and connection data.

Subsequent analysis identified a significant increase in unauthorized data transfers to the aforementioned 149.28.124[.]84 IP on another customer network, highlighting the potential broader impact of this compromise. The volume and frequency of these transfers suggested that attackers were leveraging automated data collection techniques, further underscoring the sophistication of the attack.

Darktrace’s detection of the likely exfiltration of 859.37 MiB to the endpoint 149.28.124[.]84.
Figure 4: Darktrace’s detection of the likely exfiltration of 859.37 MiB to the endpoint 149.28.124[.]84.

External research suggested that once active, the Cyberhaven extension would begin silently collecting session cookies and authentication tokens, specifically targeting high-value accounts such as Facebook Ads accounts [4]. Darktrace’s analysis of another affected customer noted many HTTP POST connections directed to a specific URI ("ai-cyberhaven"), while GET requests contained varying URIs prefixed with "/php/urlblock?args=AAAh....--redirect." This activity indicated an exfiltration mechanism, consistent with techniques observed in other compromised Chrome extensions. By compromising session cookies, attackers could potentially gain administrative access to connected accounts, further escalating their privileges [4].

Conclusion

This incident highlights the importance of monitoring not just endpoint security, but also cloud and browser-based security solutions, as attackers increasingly target these trusted and oft overlooked vectors.

Ultimately, by focusing on anomaly detection and behavioral analysis rather than static signatures and lists of ‘known bads’, Darktrace was able to successfully detect devices affected by the Cyberhaven Chrome browser extension compromise, by identifying activity that would likely have been considered legitimate and benign by traditional security solutions.

This compromise also serves as a reminder that supply chain attacks are not limited to traditional software vendors. Browser extensions, cloud-based applications, and SaaS services are equally vulnerable, as evidenced by Darktrace's detection of Balada Injector malware exploiting WordPress vulnerabilities to gain unauthorized network access [6]. Therefore, increased targeting of browser-based security tools, and a greater exploitation of OAuth and session hijacking techniques are to be expected. Attackers will undoubtedly refine their methods to infiltrate legitimate vendors and distribute malicious updates through trusted channels. By staying informed, vigilant, and proactive, organizations can mitigate exposure to evolving supply chain threats and safeguard their critical assets from emerging browser-based attack techniques.

Credit to Rajendra Rushanth (Cyber Analyst) Justin Torres (Senior Cyber Analyst) and Ryan Traill (Analyst Content Lead)

Appendices

Darktrace Model Detections

·       Compromise / Beaconing Activity To External Rare (AP: C2 Comms)

·       Compromise / Beacon for 4 Days (AP: C2 Comms)

·       Compromise / HTTP Beaconing to Rare Destination (AP: C2 Comms)

·       Device / Suspicious Domain (AP: C2 Comms, AP: Tooling)

·       Compromise / Sustained TCP Beaconing Activity To Rare Endpoint (AP: C2 Comms)

·       Anomalous Server Activity / Rare External from Server (AP: C2 Comms)

·       Anomalous Connection / Multiple Failed Connections to Rare Endpoint (AP: C2 Comms)

·       Anomalous Server Activity / Anomalous External Activity from Critical Network Device (AP: C2 Comms)

·       Compromise / Slow Beaconing Activity To External Rare (AP: C2 Comms)

·       Compromise / Repeating Connections Over 4 Days (AP: C2 Comms)

·       Anomalous Connection / Multiple HTTP POSTs to Rare Hostname (AP: C2 Comms)

·       Anomalous Server Activity / Outgoing from Server (AP: C2 Comms)

·       Compromise / High Volume of Connections with Beacon Score (AP: C2 Comms)

·       Compromise / Large Number of Suspicious Failed Connections (AP: C2 Comms)

·       Email Nexus / Connection to Hijacked Correspondent Link

·       Compromise / Suspicious TLS Beaconing To Rare External (AP: C2 Comms)

·       Compromise / Quick and Regular Windows HTTP Beaconing (AP: C2 Comms)

List of IoCs

IoC - Type - Description + Confidence

cyberhavenext[.]pro - Hostname - Used for C2 communications and data exfiltration (cookies and session tokens)

149.28.124[.]84 - IP - Associated with malicious infrastructure

45.76.225[.]148 - IP - Associated with malicious infrastructure

136.244.115[.]219 - IP - Associated with malicious infrastructure

MITRE ATT&CK Mapping

Tactic – Technique – Sub-Technique

INITIAL ACCESS - T1176 - Browser Extensions

EXECUTION - T1204.002 - Malicious Browser Extensions

PERSISTENCE - T1176 - Browser Extensions

COMMAND AND CONTROL - T1071.001 - Web Protocols

COMMAND AND CONTROL - T1001 - Data Obfuscation

CREDENTIAL ACCESS - T1539 - Steal Web Session Cookie

DISCOVERY - T1518.001 - Security Software Discovery

LATERAL MOVEMENT - T1557.003 - Man-in-the-Browser

EXFILTRATION - T1041 - Exfiltration Over C2 Channel

EXFILTRATION - T1567.002 - Exfiltration to Cloud Storage

IMPACT - T1583.006 - Session Hijacking

References

[1] https://thehackernews.com/2024/12/16-chrome-extensions-hacked-exposing.html

[2] https://www.cyberhaven.com/blog/cyberhavens-chrome-extension-security-incident-and-what-were-doing-about-it

[3] https://www.infosecurity-magazine.com/news/chrome-browser-extensions-hijacked/

[4] https://www.theverge.com/2024/12/28/24330758/chrome-extension-cyberhaven-hijack-phishing-cyberattack-facebook-ads-authentication-theft

[5] https://www.virustotal.com/gui/domain/cyberhavenext.pro

[6] https://darktrace.com/blog/balada-injector-darktraces-investigation-into-the-malware-exploiting-wordpress-vulnerabilities

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Rajendra Rushanth
Cyber Analyst

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March 19, 2025

Global Technology Provider Transforms Email Threat Detection with Darktrace

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At a glance

  • Within just one month of using Darktrace / EMAIL, the volume of suspicious emails requiring analyst attention dropped by 75%, saving analysts 45 hours per month on analysis and investigation.
  • By offloading most manual, repetitive tasks to Darktrace / EMAIL, the company’s skilled security analysts can focus on developing new capabilities and tackling more complex, rewarding projects.
  • Darktrace recently detected and blocked a highly sophisticated and personalized phishing email that spoofed a Microsoft SharePoint and Teams website and used advanced engineering to impersonate the school of an employee’s family member.
  • The transition from the incumbent solution to Darktrace / EMAIL was seamless and undetectable to the company’s vast of customers and partners, reinforcing the security organization’s role as a business enabler—protecting the company and reducing risk without adding friction.

Securing a complex, distributed business without disruption

The company remains at the forefront of technological innovation and transformation; however, its success and ambitions come with the challenges of managing a distributed global business—balancing digital advancements, existing technology investments, and evolving compliance requirements.

Optimizing a complex tech stack for scalable growth

The organization operates a diverse technology stack spanning Windows, Mac, Linux, and multiple cloud environments, creating a complex and challenging IT landscape. The company’s Chief Information Security Officer (CISO) emphasizes the need for efficiency and agility. “Our goal is to scale and deliver new capabilities without increasing headcount, ensuring that costs remain proportionate to growth.”

Balancing security, governance, and business agility

Committed to responsible practices, this industry leader prioritizes secure and trustworthy technology for its customers who rely on its solutions. “Balancing business agility with governance is a constant challenge," said the CISO. "There’s always a natural push and pull, which I believe is healthy—but achieving the right balance is delicate.”

Protecting critical workflows without impacting productivity

For the organization, email is much more than just a communication tool. “Email plays a critical role in our engineering workflows and is fundamental to how we build our products.” Because of this, the company is extremely cautious about implementing any solution that could introduce friction or disrupt productivity. “There is zero tolerance for disruption, which is why we take a deliberate and methodical approach when evaluating, selecting, and deploying our tools and solutions,” he said.  

More than a vendor: A security partner invested in success

To ensure an optimal security infrastructure, the enterprise security team regularly evaluates market technologies to their existing solutions. With the rapidly evolving threat landscape, the CISO said they “wanted to validate whether we still had best-in-class protection and the right controls in place to secure our organization. It was about assessing whether we could do better in our ongoing effort to fine-tuning our approach to achieve the best possible outcome.”

The team evaluated 15 different email security vendors based on the following criteria:

  1. Efficacy to detect threats
  2. Ability to integrate with existing tooling
  3. Ease of use
  4. A vendor’s approach to partnership  

They initially narrowed the list to five vendors, conducting demo sessions for deeper evaluations before selecting three finalists for a proof of value (POV). We analyzed actual malicious emails with each vendor to assess the accuracy of their detections, allowing for an objective comparison,” said the CISO. Through this rigorous process, the Darktrace / EMAIL security solution emerged as the best fit for their business. “Darktrace’s product performed well and showed a genuine commitment to partnering with us in the long-term to ensure our success.”

The team objectively understood where there were gaps across the different vendors, where they were strong, and where they could use improvement. “Based on the analysis, we knew that Darktrace / EMAIL could deliver as the data supported it, in our specific use cases.  

Partnership, integrity and respect

Throughout the evaluation process, the importance of partnership and mutual respect remained an essential factor to the CISO. “I wanted a company we could develop a long-term strategic partnership with, one that could extend far deeper than just email.” A key factor in choosing Darktrace was the commitment and engagement of its team at every level of the organization. “Darktrace showed integrity, patience and a genuine investment in building a strong relationship with my team.  That's why we're here today.”

“Together, we've delivered some fantastic outcomes”

For the organization, Darktrace / EMAIL has played a crucial role in reducing risk, empowering analysts, and enabling a lean, effective security strategy. “Together, we've delivered some fantastic outcomes,” said the CISO.  

Reducing risk. Empowering analysts

“Within that first month, we saw a 75% drop in suspicious emails that that required manual review, which reduced the time my team spent analyzing and investigating by 45 hours per month,” said the CISO. The security team values Darktrace / EMAIL not only for its ease of use but also for the time it frees up for more meaningful work. “Giving my team the opportunity to tackle complex challenges they enjoy and find more stimulating is important to me.” As they continue to fine-tune and optimize balance levels within Darktrace / EMAIL, he expects even greater efficiency gains in the coming months.

Maximizing protection while staying lean

It’s important for the security group to be proportionate with their spending, said the CISO. “It's all about what is enough security to enable the business. And that means, as our organization grows, it's important that we are as lean and as efficient as possible to deliver the best outcomes for the business.”  Embracing an AI-powered automated approach is an essential component to achieving that goal. By offloading most manual, repetitive tasks to Darktrace / EMAIL, the company’s skilled security analysts can focus on more strategic and proactive initiatives that enable the business.  

Protecting employees from advanced social engineering threats

Recently, Darktrace detected a malicious email targeting an employee, disguised as a spoofed Microsoft SharePoint and Teams website. What made this attack particularly sophisticated was its personalization — it impersonated the school where the employee’s family member attended. Unlike mass malicious emails sent to thousands of people, this was a highly targeted attack, leveraging advanced social engineering tactics to exploit connections within the education system and between family members.  

Protecting without disrupting

A seamless migration is often overlooked but is critical to success for any organization, said the CISO. With a wide ecosystem of partners, email is a highly visible, business-critical function for the organization — "any friction or downtime would have an immediate impact and could throttle the entire business,” he said. However, the transition from their previous solution to Darktrace / EMAIL was exceptionally smooth. “No one realized we changed providers because there was no disruption — no incidents at all. I cannot emphasize just how important that is when I'm trying to position our security organization as an enabling function for the business that protects and reduces risk without adding friction.”

A security partnership for the future

“To survive as a business over the next few years, adopting AI is no longer optional—it’s essential,” said the CISO. However, with the cybersecurity market becoming increasingly saturated, selecting the right solutions and vendors can be overwhelming. He stresses the importance of choosing strategic partners who not only deliver the outcomes you need, but also deeply understand your organization’s unique environment. “You’re only as strong as your partners. Technology innovation and the cybersecurity market are always changing.  At some point every solution will face a challenge—it’s inevitable. The differentiator will be how people respond when that happens.”  

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