EXPLORE

Article

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)

Back to Blog Posts

Article

Ransomware Trends & Data Insights: July 2026

INC Ransom was the most active threat group in July, while activity remained relatively distributed among multiple threat groups, with 19 unique groups observed throughout the month. Alongside INC Ransom, Qilin, Global Secret Group, Anubis, and DragonForce rounded out the five most active threat groups observed in July. Several emerging threat actors were also observed during the month, including Booba Team, Settra, and Global Secret Group.

Figure 1. Activity from the top 3 threat groups in July 2026

 Throughout the month, analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities:

  • In July 2026, Global Secret Group emerged as a new threat actor, leveraging the leaked LockBit 3.0 (LockBit Black) source code. Although the group began operations in June 2026, it quickly accumulated a substantial number of victims on its data leak site (DLS). The group operates through TOR-based negotiation portals and qTox communications. Notably, its DLS provides step-by-step guidance on purchasing Bitcoin, including references to Coinbase and Binance, demonstrating a streamlined, victim-focused extortion process designed to simplify ransom payments.

  • Similar to Fulcrumsec, the recently emerged Settra ransomware group appears to leverage AI-driven analysis of stolen data, publishing detailed and highly structured victim reports on its DLS. Additionally, a potential EDR-disabling tool, edr_blind.exe, was identified in multiple cases, suggesting a focus on defense-evasion capabilities.

  • With the continuation of the FortiBleed campaign, researchers have now identified compromised FortiGate credentials being leveraged by both the INC and Lynx ransomware operations. Analysis revealed direct operational links between the groups, including shared ransomware infrastructure and overlap between FortiBleed victims and ransomware targets. The operators are also incorporating AI to enhance various stages of the attack lifecycle and increase operational efficiency and scale. Notably, Arete also observed an INC ransomware intrusion leveraging FortiBleed-derived access in July, reinforcing the campaign's role as a precursor to ransomware deployment.

Sources

  • Arete Internal

Podcast

Cyber Campfire: June Threat Trends & Insights

In this episode of Arete’s Cyber Campfire podcast, our Threat Intelligence Team discusses trends, statistics, and emerging threat actors from June 2026. Tune in for firsthand insights on today’s threat landscape that can enhance your approach to cyber risk.

Article

Current: Misconfigured Server Reveals Multiple Phishing Campaigns

Researchers uncovered three Microsoft 365 phishing campaigns after discovering a misconfigured HTTP server that exposed a threat actor’s phishing tools, configurations, victim logs, and operational infrastructure. The investigation revealed two operators using custom Evilginx-based adversary-in-the-middle (AiTM) phishing frameworks to steal authentication sessions and bypass MFA protections. A third operator abused Microsoft’s OAuth Device Code flow by tricking victims into completing authentication through Microsoft’s legitimate login process, allowing attackers to obtain valid access and refresh tokens without stealing passwords. The largest campaign compromised at least 218 victims across 12 countries, primarily targeting corporate Microsoft 365 accounts, with refresh tokens enabling persistent access. Researchers also identified the use of remote management tools for maintaining access, AI-assisted development of phishing tooling, and links to broader Phishing-as-a-Service (PhaaS) ecosystems, highlighting how commodity frameworks and automation are lowering the barrier for sophisticated identity-based attacks.

What’s Notable and Unique

  • The campaigns demonstrate the continued shift from traditional credential theft to identity- and token-based compromise, in which attackers target authentication sessions, cookies, and OAuth tokens rather than relying solely on password theft. By obtaining valid authentication artifacts, attackers can access Microsoft 365 environments while bypassing conventional MFA protections.


  • The use of Evilginx-based AiTM frameworks highlights how publicly available phishing tools have evolved into effective MFA-bypass platforms. These frameworks proxy legitimate login pages, capture authenticated sessions, and allow attackers to reuse valid sessions without requiring victims’ credentials again.


  • The OAuth Device Code flow abuse represents a different attack method, in which attackers leverage a legitimate Microsoft authentication mechanism to obtain tokens after victims approve the request. This approach bypasses password theft entirely by abusing trusted authentication workflows.


  • The exposed infrastructure provided insight into attacker operations, including phishing configurations, victim tracking data, remote administration tools, and evidence of AI-assisted development. The findings demonstrate how phishing ecosystems now provide reusable tooling and automation that reduce the technical expertise required to conduct large-scale identity attacks.

Analyst Comments

These Microsoft 365 phishing campaigns demonstrate the ongoing evolution of identity-focused attacks, as adversaries increasingly target authentication sessions, tokens, and legitimate cloud authorization mechanisms to bypass traditional security controls. The combination of AiTM phishing, OAuth abuse, remote management tools, and PhaaS infrastructure enables threat actors to maintain persistent access while blending into legitimate cloud activity.

The growing availability of phishing frameworks and AI-assisted attack development highlights the need for continuous identity security improvements beyond traditional phishing defenses. Arete recommends that organizations strengthen identity monitoring, adopt phishing-resistant MFA where possible, review OAuth application permissions, monitor token activity, and implement conditional access policies to detect and restrict suspicious Microsoft 365 authentication behavior. Security teams should also monitor post-compromise indicators such as abnormal mailbox access, suspicious application consent, unauthorized remote tools, and unusual sign-in activity.

Sources

  • One Misconfigured Server, Three Active Campaigns: Full exposure of three AiTM Phishing Operators

  • Misconfigured Server Reveals Three Evilginx Phishing Operations Targeting Microsoft 365

Podcast

Digital Forensics Meets the Courtroom: Insights on Expert Witness and Cyber-Related Litigation

In this episode of Bytes of Insight, host Vinny Sakore and special guest Dr. Bruce Hartley, Managing Director and Co-Founder of Advisory Services at Arete, discuss the evolving role of digital forensics and expert witness work in cybersecurity litigation. Tune in for firsthand insights on how Arete conducts post-breach investigations, what it takes to undergo cross-examination on the stand, and how emerging threats like AI-driven social engineering and third-party breaches are reshaping the advisory landscape.