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Conti Ransomware is the New Ryuk?

Arete Analysis

Summary 

Arete’s Threat Intelligence team observed that Conti ransomware could be a rebrand of Ryuk ransomware, as both variants use similar tactics to deploy ransomware executables. 

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Background 

Based on analysis of Conti ransomware, which was originally spotted in the wild in February of this year, the Arete Threat Intelligence team believes that this variant is being operated by the same group that conducted Ryuk ransomware attacks in the past. Digital forensics analysis of systems impacted by Conti ransomware revealed that it is generally being deployed by the attackers using the TrickBot banking trojan. Since early 2019, Ryuk ransomware operators exclusively used TrickBot trojan in their operations. In the 1st quarter of 2020, the number of Ryuk ransomware attacks significantly declined while the number of new Conti matters started to rise, which is a secondary indicator of a connection between both variants. 

Conti Overview

Conti is a sophisticated ransomware variant that emerged in February 2020. Unlike most of its’ peers, Conti ransomware encrypts files on victims’ machines significantly faster by running 32 concurrent threads and utilizing all computing power that impacted systems have available. As a result of that, devices with multi-core CPUs get encrypted quicker. Conti has the capability to encrypt local hard drives, network shares and other devices on the local network. To encrypt the data, Conti uses the AES-256 encryption key, which is bundled with the RAS-4096 public encryption key (Note: this key is unique for each victim). Since the encryption key is unique for each victim, Conti operators cannot provide a decryption tool, which would work only on specific devices. The Conti decryption tool works on all encrypted systems within a victim’s networks. 

Prior to the start of the encryption, Conti leverages Windows Restart Manager to disable security, backups and other applications that may keep files locked on the impacted systems. Then it deletes Shadow Volume copies to make it impossible to use built-in Windows volume backups to restore data after the encryption. 

Once encryption completes, the .CONTI extension is added to all encrypted files and the ransom note, CONTI_README.txt, is placed in each folder. Each ransom note contains 2 email addresses to get in touch with the attackers, which are unique for each victim. This method is consistent with what Ryuk operators used in their attacks. Conti operators use a unique set of emails to identify each victim, so it does not matter if a victim responds from a corporate account or from a public email account – attackers still will know which victim they are communicating with. Just like Ryuk, Conti conducts research into information about their victims and sets ransom demands based on what they believe the victim can afford to pay. 

Conti Ransom Note

Figure 1 - % of Data Exfiltration in Ryuk matters

It was uncommon for Ryuk to exfiltrate data from victims’ systems. Based on Arete analysis of previous matters, we only observed data exfiltration in 7% of cases. Unlike Ryuk, it appears that Conti ransomware operators decided to join the bandwagon of other 20+ variants that steal data from victims’ environments prior to the encryption. Conti also created a web site where they publish lists of their victims in attempt to improve their chances of getting paid. In the last few weeks, Conti stepped up their extortion attempts and, in some cases, called the owner/managers of companies directly, to inform them that they have been compromised and threaten them to release the stolen data if they don’t pay. 

Security Recommendations

Below are a few recommendations that will help to protect your organization from Conti ransomware attacks: 

  1. Implement a sophisticated Endpoint Detection & Response (EDR) solution that will rely on behavior analysis, instead of just malware signatures, and have tamper-proof capabilities. 

  2. Keep your systems updated and disable SMBv1, to protect against Windows EternalBlue vulnerability, which is actively being used by the TrickBot banking trojan to propagate within a victims’ environment. 

  3. Block outbound traffic on your firewall for ports 447, 449 & 8082 (Note: along with 443 those ports are commonly used by TrickBot) and implement geo-blocking for foreign countries that you don’t have any employees in and don’t do business with.

  4. Continuously educate your users on how to identify suspicious phishing emails and attachments. 

  5. Implement an off-site backup solution and test it regularly 

Figure 2 - Screenshot of the Conti exfil site

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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

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Helix Extortion Group Debuts in SharePoint Data Theft Attacks

A newly identified data-extortion group, Helix, is reportedly conducting targeted campaigns by exploiting identity-based attack techniques to gain access to Microsoft 365 environments and exfiltrate data from SharePoint Online. The group leverages voice phishing (vishing), device code phishing, and multi-factor authentication (MFA) abuse to compromise user accounts and establish unauthorized access. 

  • Helix threat actors reportedly initiate intrusions through vishing campaigns, impersonating trusted individuals—often the target's manager—and leveraging caller ID spoofing to enhance credibility. 


  • The actors then attempt to persuade victims to complete device code phishing workflows, enabling unauthorized access to corporate accounts and Microsoft 365 resources. 


  • Following successful authentication, the actors conduct reconnaissance and enumeration of SharePoint environments before identifying and exfiltrating sensitive data for extortion purposes. 


  • Helix's variable dwell times suggest a flexible, target-specific operational approach, enabling the group to adapt its intrusion timeline to victim environments to maximize data theft and extortion opportunities while minimizing the likelihood of detection. Helix's operations also appear to be focused on large-scale data theft and extortion, with an emphasis on automated SharePoint data exfiltration following successful credential or session compromise.

Overlaps with Other Extortion Groups

Researchers assess that Helix likely emerged from or has operational overlap with the ShinyHunters and BlackFile/Redact cybercriminal ecosystems. ShinyHunters historically focuses on compromising websites, developer repositories, and exposed credentials or API keys to gain access to corporate cloud environments, monetizing stolen victim data on the dark web. BlackFile utilizes identity-centric and social engineering–driven methods of intrusion, relying less on traditional malware and instead leveraging credential theft, privilege escalation, rapid data exfiltration, and coercive tactics such as swatting to maximize extortion pressure. In May 2026, BlackFile announced that it would be rebranding as “Redact” (which may have later rebranded again to “Pink”), yet despite the rebrands, threat actors operating within these groups continued to exhibit similar operational models, victimology, and extortion methodologies.  

Analyst Comments

Collectively, the similarities between the groups suggest the possibility of a shared criminal ecosystem, affiliate network, or loosely connected threat cluster rather than entirely independent operations.  The emergence of Helix further reflects the broader trend of extortion groups rebranding or fragmenting while retaining proven attack techniques and operational infrastructure to support their criminal activities. Despite suspicion of these groups’ connectivity, the exact nature of the relationship remains unconfirmed.  As Helix focuses on identity-based attack techniques to gain access to Microsoft 365 environments, Arete recommends that organizations remain vigilant in using MFA, enforcing strong identity security controls, continuously monitoring authentication activity, and enhancing user awareness of social engineering tactics.

  • Sources

  • Helix, a New Name in the Data Extortion Ecosystem?

  • BlackFile actively extorting data-theft victims in retail and hospitality sector

  • "Pink" Data Extortion Group Hunting With Evasive Phishing Kits