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US Government Alerts of Imminent Attacks Against the Healthcare Sector by Trickbot Group

Arete Analysis

Executive Summary

Last week,  the Cybersecurity and Infrastructure Security Agency (CISA) in collaboration with the Federal Bureau of Investigation (FBI), and the Department of Health and Human Services (HHS) released the following alert: AA20-302A – Ransomware Activity Targeting the Healthcare and Public Health Sector.

The alert informs that there is credible intelligence of an increased and imminent cybercrime threat to U.S. hospitals and healthcare providers associated with the Trickbot and BazarLoader trojans that often leads to ransomware like the Ryuk and Conti ransomware. The alert also mentions the Trickbot Anchor tool set and Anchor DNS tool developed by this group.

News of these attacks against the Healthcare sector are of special concern due to the recent increase of COVID-19 cases in the US and evidence that shows ransomware attacks against the healthcare sector have been associated with persons losing their lives due to services being routed to nearby hospitals and laboratory results not being quickly delivered electronically to the providers.

Arete statistics and Intel from Arete’s Fusion Center and Open-source intelligence (OSINT) shows that this new wave of attacks since October 2020 have a slight change in TTPs and the BazarLoader malware has now been observed in systems compromised with Ryuk.

The Arete incident response (IR) practice has responded to more than ninety (90) Ryuk engagements since 2019 with more than six breach responses engagements just in the month of October 2020.

Based on Intelligence gathered from our DFIR cases, Arete’s Fusion Center had developed countermeasures deployed in the SentinelOne EDR platform to detect these threats and our Managed Detection and Response (MDR) team has been handling detections at our client’s sites.

This article is meant to share with the community Arete’s statistics and our assessment based on breach response engagements.

Statistical Data from Arete’s Metrics

The information listed below is based on Ryuk cases investigated by Arete IR since January 2019. Our IR and Data Analytics practices work together to track key data points for every ransomware engagement.  Our IR practice tracks data points on the ransomware variant and collects statis-tics based on handled engagements:

  • Since 2019, Arete has responded to Ryuk cases in some of the following sectors:

Healthcare: 19 | Professional Service: 28 | Public services: 21 | Manufacturing: 11 | Technology/Engineing/ Telecom: 6 | Critical Infrastructure: 1

  • Average duration of business downtime: 9.47 days

  • Average original ransom demand in bitcoin: 125.39 BTC

  • Average final ransom demand in bitcoin: 72.58 BTC

  • Average ransom demand paid in US dollars: $621,064.05

  • Minimum ransom demand paid in US dollars: $10,000.00

  • Maximum ransom demand paid in US dollars: $5,177,510.78

  • Remote access is the most common method of intrusion found 39.34% of the times

  • During the Ryuk dwell time this year, Arete responded to ten (10) Conti ransomware engagements

Ryuk Ransomware Overview

Since August 2018, a Russian-based cybercrime group has been operating a ransomware known as Ryuk (a customized version of Hermes commodity ransomware).

The industry saw a sudden drop of Ryuk, starting around the time that COVID-19 had its major impact in March 2020. This is also around the same time that a very similar, Conti ransomware, began to kick-off, leading many to believe that Conti was merely a rebrand of Ryuk. The data suggests though that it is possible that Conti was a failed rebrand since Arete IR has not been engaged with Conti infected clients since Ryuk attacks started again in October 2020.

Ryuk typically compromises networks through Trickbot, or Emotet then delivering Trickbot. Trickbot has recently been in the news in the cyber industry due to Microsoft’s approval via a court order to engage in disruption efforts of this botnet. With this active disruption campaign, it is possible that the sudden return and up-tick of Ryuk infections is due to the Russian cybercrime group acting in retaliation utilizing their more mature ransomware product, Ryuk, as opposed to the potentially rebranded, Conti, which could still have been in a testing phase. This is based on the sudden stop of Conti and up-rise of Ryuk in line with the disruption efforts from Microsoft.

According to Microsoft, they initially disabled sixty-two (62) of the initially identified sixty-nine (69) Trickbot servers. Almost immediately, fifty-nine (59) new servers were attempted to be added to the Trickbot infrastructure. As of October 20, 2020, fifty-eight (58) of the new servers have also been disabled leaving a total number of eight (8) known active Trickbot servers.

Ryuk Wave Crashing on US Healthcare

Of the more than ninety (90) total Ryuk ransomware engagements that Arete IR has led since May 2019, nineteen (19) of those engagements were for a client in the healthcare industry (23%).  Out of the seven (7) engagements of Ryuk ransomware that Arete IR has led since it re-emerged in October 2020, the most recent case is the only client that is in the healthcare industry (14%). This evidence shows it is not typical for Ryuk attacks to be focused primarily on the healthcare industry. This could further backup the theory that the impending Ryuk wave of attacks on the healthcare

industry could be retaliation for Microsoft’s disruption campaign against the Trickbot infrastructure that Ryuk is known for utilizing for initial intrusion.

Recommendations

  • Install an Endpoint Detection and Response (EDR) solution with the capability to halt detected processes and isolate systems on the network, based on identified conditions

  • Block: Any known attacker C2s in the firewall; A high number of SMB connection attempts from one system to others in the network over a short period of time

  • Implement: A system enforced password policy to force users into changing passwords at least every 90 days; Multifactor authentication (MFA) on RDP and VPN access

  • If not needed, eliminate vulnerable RDP ports exposed to the internet

  • Perform: Dark web monitoring periodically to verify if data from the organization is available for sell in the black market; Penetration tests • Periodically patch systems and update tools

  • Monitor: Connections to the network from suspicious locations; Downloadsuploads of files to file sharing services over non-standard hours, not commonly used in the organization, etc; Uploads of files from Domain Controllers to the internet; Network scans from uncommon servers (e.g. RDP server)

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Article

Europol Disrupts AudiA6 Crypto Laundering Service

European authorities have dismantled AudiA6, a major cryptocurrency laundering service linked to ransomware groups and broader cybercriminal networks. Between 2022 and 2025, the platform is believed to have processed over €336 million in illicit funds, enabling threat actors to obscure financial trails and monetize cybercrime proceeds. Its operators are also suspected of running Dark2Web, a dark web forum that facilitated collaboration, services, and connections among cybercriminals globally. This development underscores the expanding role of sophisticated, large-scale cryptocurrency laundering services in sustaining the cybercrime economy, enabling threat actors to obscure illicit funds and evade regulatory controls.

What’s Notable and Unique 

  • Following law enforcement disruption of Cryptex and Garantex, AudiA6 emerged as another platform involved in financial activities linked to ransomware groups. Investigators believe that AudiA6 became a central hub for cybercriminals seeking to launder stolen digital assets while obscuring the transaction trail from authorities.

  • On June 10, 2026, a coordinated operation resulted in two arrests in Georgia, the dismantling of key infrastructure (30+ servers, 25 domains), the freezing or seizure of over €778,000 in crypto, and the takedown of the AudiA6 and Dark2Web platforms. 

Analyst Comments

Ransomware groups and cybercriminal networks are increasingly leveraging sophisticated techniques, including chain-hopping, decentralized exchanges, and mixer-as-a-service platforms, to rapidly move illicit cryptocurrency across multiple blockchains, effectively obscuring transaction trails. Concurrently, the widespread use of fraudulent exchange accounts, mule wallets, and privacy-enhancing tools has elevated cryptocurrency laundering to a core enabler of the cybercrime ecosystem, allowing actors to bypass anti-money-laundering controls at scale. This investigation identified over 6,000 KYC records linked to money-mule accounts, many of which were tied to Russian-speaking intermediaries specifically recruited to facilitate the movement of illicit proceeds. These threat actors systematically used both commercial and domain-controlled email services to establish mule accounts across multiple cryptocurrency platforms. Collectively, these findings underscore the growing scale, coordination, and professionalization of cryptocurrency-enabled crime, highlighting the critical need for sustained, intelligence-led, and internationally coordinated efforts to disrupt these evolving financial ecosystems.

Sources

  • Ransomware gangs cut off from EUR 336 million ‘AudiA6’ crypto laundering pipeline

Article

Threat Actors Leverage AI for EDR Evasion

A threat actor has developed and deployed a ransomware attack toolkit enhanced with AI-assisted development workflows, enabling automated Active Directory (AD) discovery and improved EDR evasion capabilities. The toolkit leverages agent-based AI systems, such as Claude’s Opus and Cursor agents, for iterative malware development, testing, and refinement. 

What’s Notable and Unique 

  • Researchers have highlighted that this toolkit can not only generate ransomware code but also bypass sophisticated security defenses and identify AD networks for malware distribution. 

  • The framework incorporates multiple capabilities, including automated AD discovery and reconnaissance mechanisms, iterative EDR testing environments to refine evasion techniques, and a command-and-control (C2) infrastructure that leverages Telegram APIs and Cloudflare redirectors for stealth. 

  • Additionally, some agents were tasked with checking security research and technical posts for various bypass techniques. The agents recognized what was required for reproduction, extracted the techniques, mapped them to the MITRE ATT&CK knowledge base of adversary behaviors, set up a test lab, carried out the methodology, and reported the results. 

  • After a few repetitions, the modules seemed to avoid nearly all EDR solutions, despite the agent’s initial suggestion of a high failure rate. Although researchers found no evidence that AI was embedded in deployed malware or was operating independently in victim environments, the technology was still used to accelerate the iterative process of developing, testing, and refining payloads against security products, shortening the period between the publication of offensive security research and its practical implementation by threat actors. 

Analyst Comments 

AI-driven tools like this could accelerate the pace and sophistication of ransomware attacks, enabling even relatively inexperienced actors to launch high-impact campaigns. This development underscores the urgent need for security solutions to adapt to AI-assisted threats. Organizations must respond by strengthening detection engineering, improving visibility across environments, and maintaining robust security fundamentals.  

Sources 

  • AI-built ransomware toolkit automates EDR evasion, AD discovery  

  • Pointing a Cursor at evading detection

Article

Arete's 2026 Q1 Crimeware Report

Harness Arete’s unique data and expertise on extortion and ransomware to inform your response to the evolving threat landscape.

Article

CMS Vulnerability Leads to ClickFix Campaign

Threat actors compromised at least 700 education and technology websites in a recent ClickFix campaign by exploiting a critical SQL injection flaw (CVE-2026-26980) in the Ghost content management system (CMS). Adversaries combined the vulnerability with the ClickFix social engineering tactic to steal admin keys and inject a malicious JavaScript that delivers a fake Cloudflare or CAPTCHA verification pop-up, tricking victims into copying and pasting a malicious command into their systems.

What’s Notable and Unique

  • Rather than targeting the end user first, this campaign is unique in its initial exploitation of the system, followed by social engineering attempts. This hybrid attack style is likely being leveraged to bypass traditional defenses.

  • This recent campaign also highlights how trusted web properties can be weaponized at scale and coupled with unpatched CMS vulnerabilities. Rather than using the CMS compromise to perpetrate a single attack, threat actors turned it into a supply-chain attack that ultimately affected over 700 trusted websites.

Analyst Comments

As network defenders and their tools enhance threat detection capabilities, adversaries increasingly seek methods to bypass these defenses. By combining vulnerability exploitation, social engineering techniques, and staging for ancillary attacks, this campaign successfully bypassed traditional defenses and inflicted significant impact. Defending against hybrid cyberattacks requires comprehensive security controls beyond simply patching vulnerabilities. Organizations should focus on limiting movement within the environment, detecting abuse of trusted applications, and preventing end-user manipulation.

Sources

  • 700+ education and tech websites hijacked in huge ClickFix malware campaign

  • Under the engineering hood: Why Malwarebytes chose WordPress as its CMS

  • Think before you Click(Fix): Analyzing the ClickFix social engineering technique

  • Ghost CMS Vulnerability Exploited to Infect 700 Sites With ClickFix Malware