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Darkside Ransomware: Caviar Taste on Your Big-Game Budget

Arete Analysis

Summary

Explore Darkside ransomware, an operation utilizing sophisticated tactics to target high-revenue organizations. Arete’s threat intelligence data reveals high ransom demands, extensive business downtime, and universal data exfiltration.  

By all appearances, the proprietors of Darkside ransomware mean business. 

With their sights set on organizations with US$4M+ in revenue, they’re about high-value, big-game targets and they’ve got the skills and experience to bring in some big hauls.

The Darkside group demonstrates seasoned experience, polished business acumen, and an ability to quickly respond to both negative and positive stimuli within their sphere of market influence. They exhibit similarities to notable ransomware operations, such as LockBit and REvil, and they take an outwardly aggressive posture toward the security industry, taunting companies like BitDefender and Coveware. 

Statistical data on Darkside ransomware from Arete engagements 

The information below is based on Darkside events that the Arete IR team has investigated since November 2020. Our incident response and data analytics practices work together to track key data points and collect statistics on variants for every ransomware engagement.

Sectors of clients affected by this threat:

Professional Services | Manufacturing

  • Average Ransom Demand: US $6,527,402.02

  • Highest Ransom Demand: US $10,054,804

  • Lowest Ransom Demand: US$3,000,000

  • Average business downtime: 5 days

  • Data exfiltration observed in 100 percent of cases

Key observations

Based on the Arete Cyber Threat Intelligence (CTI) team’s assessments:

Darkside ransomware operators are likely conducting long-tail reconnaissance of the victim environment for up to two (2) weeks prior to deploying their payloads. 

  • The earliest known point of malicious activity for a select event was noted when forensic discovery indicated installation of the MetaSploit framework on the victim’s domain controller fifteen (15) days prior to enterprise-wide, automated deployment of Darkside. 

Yes, we expect Darkside to be big-game hunters. Forbes quoted them as saying they will target “only those who can afford to pay.” Their recruitment advertisements echo this assertion. 

  • Darkside proprietors and operators come from an established pedigree. 

  • They are transparent in their description of operational mistakes and they renumerate operators for lost revenue. 

  • They taunt BitDefender and Coveware directly with aggressive and forthright assertions of their intent. 

  • As recently as December 27, 2020, a Russian-speaking cybercriminal actor using the handle ‘darksupp’ invited media outlets and data recovery organizations to follow a new “Press Center” section at the Darkside “name-and-shame” leak site. Darksupp allegedly stated that this press center would enable media and recovery firms to ask questions about recent attacks while also giving recovery organizations access to a dedicated chat room, where they could enroll in a “loyalty program” for discounts on data decryption. 

  • The group has underwritten their aspirations with a substantial surety bond (approx. US$350k) and assert that they are willing to increase their guarantee to inspire further confidence in the right partners. 

  • Their first and now exclusive appearance on XSS (reboot of DamageLab) along with exploitation of their endorsements/acceptance from known Russian-speaking actors underpins the Arete CTI team’s current assessment of their maturity and client knowledge. 

  • On November 10, 2020, a Russian-speaking cybercriminal actor using the handle ‘darksupp’ announced the launch of an official recruitment effort for affiliates to participate in the Darkside Ransomware-as-a-Service (RaaS) affiliate program. 

  • Darksupp received a forum-public favorable review on XSS from actor Quake3 (aka LockBit), proprietor of the LockBit RaaS platform. 

  • The proprietor(s) behind the ‘darksupp’ persona tout seasoned experience with and feature influence from notable ransomware operations, such as LockBit and REvil. 

  • Darkside operator affiliates are likely using Whitebit (e.g., Whitebit[.]com) to cash out, given observed wallet transactions and ledger analysis by Arete. 

Detailed information

On August 8, 2020, operators of the Darkside ransomware announced their malware in a press release on the dark web. They stated that they had created their ransomware because they could not find the perfect product for their needs and had made millions of dollars by partnering with other well-known ransomware groups. In the same release, they also said they would not be targeting the healthcare, education, non-profit, and government sectors.  

On November 11, 2020, Darkside announced their RaaS model, inviting partners and affiliates to work with them. They also announced the development of a distributable data storage system, calling out the use of servers in Iran and unrecognized republics to prevent victim organizations from taking down their operations.

Figure 1. Darkside announces their service.


Figure 2. Darkside announcement of their RaaS product, distributed storage system, and invitation to partners and affiliates to work with them.

After this announcement, multiple news outlets began reporting that the group was using servers in sanctions countries like Iran. In response, the Darkside group updated their storage announcement on November 15, 2020, stating: 

  • The storage system is still in the planning stages and has not yet launched. 

  • They are not citizens of Iran, and leaked company data is not and will not be hosted in Iran. 

  • They are still considering where to host the leaked data, but it would not be in a region on the sanctions list. 


Figure 3. Darkside makes an updated announcement, that they will think where to host leaked data on servers that are not in sanctions countries.

The above business model makes total sense from the threat actors’ perspective. If the data were stored on servers in regions on the U.S. Treasury Department’s Office of Foreign Asset Control (OFAC) sanctions list, the actors would be unable to obtain ransom payments from victims.

The Arete CTI team and other researchers in the community found that the group has been advertising their services on well-known Russian hacker forums, with posts written in Russian. 


Figure 4. Darkside group advertising on a well-known hacking forum (Source: SentinelOne)


Figure 5. A Google translation of Darkside advertisement on a well-known Russian hacking forum (Source: SentinelOne)

Based on language analysis, a native Russian-language speaker wrote the posts. What’s more, the group’s ransomware is designed to avoid infecting systems in Commonwealth of Independent States (CIS) countries, including Russia. In the past, other Eastern European threat actor groups have done the same to try to avoid getting in trouble with local law enforcement agencies. The Arete CTI team also conducted blockchain analysis of previous ransom payments and did not find any ties between sanctioned entities/money service businesses (MSBs) and Darkside money-laundering operations. 

As leaders in the community and especially in the current COVID-19 climate, we need to join forces to properly inform the public without causing worldwide panic and help ensure our clients’ quick recovery from attacks and return to normal business operations. If a company were to make a rash decision about ransom payments based on negligent reporting, it could prevent file restoration and ultimately, shutter a business and cost employees their livelihood. 

Darkside high-level technical overview

While tactics, techniques, and procedures (TTPs) may vary amongst operators, it’s important to note that Darkside caters to semi-exclusive affiliates, likely of Russian or Eastern European origin. They likely pool their technical experience — both successes and failures — from this exclusive cultural enclave to orchestrate their intrusions and execute on their objective as outlined below: 

  • Darkside ransomware is primarily geared toward Windows systems, however, the proprietor ‘darksupp’ claims the ability to develop payloads that also target Linux OS variants. 

  • We have observed the builder module screens for the control panel, and we are aware of the existence of Linux ELF-executable payloads. We assess this to be true, with high confidence. 

  • Given observed use of MetaSploit and potentially other Offensive Security Tool (OST) frameworks — always contingent on operator/affiliate preference — it’s likely that Darkside ransomware operators leverage these same tools to enumerate vulnerabilities of victim networks, where externally facing systems of interest are exposed, to establish initial access. 

  • We observed actors pivoting from having Administrator RDP sessions on the Domain Controller, to accessing another privileged account to access a file server. Thus, it’s highly likely that their two weeks in the environment afforded them precision-targeting abilities. They took their time hunting. 

  • On November 25, 2020, ‘darksupp’ claimed to have launched a content delivery network (CDN) for storing and delivering compromised data exfiltrated from victims of Darkside ransomware. The actor also claimed to be developing a second version of the ransomware and intends to provide support for distribution using dynamic-link library (.dll) and PowerShell scripts (.ps1) for deployment. 

    • We have observed Darkside operators manually enumerating and exfiltrating data using a combination of RDP access and their own copy of QTBrowser, 7zip. This culminates in a direct upload of files to both PrivatLab and MegaUpload cloud hosting, under cover of Web/HTTPS sessions, which are difficult to sift in many cases for less mature organizations. \

    • This manual methodical exfiltration occurred over the span of several hours. 

    • 7zip archives were named after data/folder names enumerated and temporarily stored in root temp directory (e.g., C:Temp, C:Temp1, C:Temphr{archive}.7z). 

  • We observed Darkside payload (e.g., azure_agent.exe.exe) staged on the domain controller in a network-shareable folder (e.g., C:WindowsIMEazure), followed by the establishment of a scheduled task (e.g., WindowsSYSVOLdomainPolicies{L0NGMGU1D}UserPreferencesScheduledTasks) set with Group Policy and instructing hosts to obtain and execute the payload. This resulted in a fully automated enterprise-wide deployment less than 24 hours after data was exfiltrated. 

Security Recommendations  

  1. Implement a sophisticated endpoint detection and response (EDR) solution that will rely on behavior analysis — not just malware signatures — and have tamper-proof capabilities. 

  2. Implement multifactor authentication (MFA). 

  3. Implement an email security solution to detect and protect against known and unknown threats. 

  4. Hunt for unusual remote desktop protocol (RDP) connections. 

  5. Use Group Policy Software Restriction Policies (SRP) to prevent users from executing Windows executable filetypes (e.g., .exe, .dll, .hta, .bat, .scr) from the AppDataLocalTemp path of Office365, Microsoft Word, Excel, and Outlook. Alternatively, also inspect C:Users[current user]AppDataRoamingMicrosoft as it’s another popular method that achieves the same results. 

  6. Implement and regularly test an off-site backup solution. 

Appendix

Indicator

Role

C:\Windows\IME\azure

File path of DC where Darkside payload was staged.

F:\temp

File path of staged 7zip archives (.7z) prior to exfiltration

F:\temp1

File path of staged 7zip archives (.7z) prior to exfiltration

F:\temphr

File path of staged 7zip archives (.7z) prior to exfiltration

Windows\SYSVOL\domain\Policies\{LONGMGU1D}\User\Preferences\ScheduledTasks

Path of Scheduled Task on Domain Controller for deployment of Darkside payload via Group Policy.

Indicator

Role

azure_agent.exe.exe

Darkside Payload

README.3a43168b.TXT

Darkside Ransomware Note – README.{random_string}.TXT

enc.exe

Darkside Payload

idfoodsf.exe

Darkside Payload

Indicator

Role

6d134cdf470f03707ad481b617e67b9018f92f72a0e2fb3e6cc9f2ab17ac1439

Darkside Payload

06cfe7f5d88e2f7adda6d8333ca8b302debb22904c68a942188be5730e9b3c8

Darkside Payload

243dff0fc80a049f4fb3729f8b8def0fce29768f345c88ee1069e22b0ae60

Darkside Payload

0839aabe5fd63b16844a27b3c586c02a044d119010a1a40ee4035501c34eae0d

Darkside Payload

Indicator

Role

www[.]privatelab[.]com

Manual Data Exfiltration – Cloud Upload

www[.]mega[.]nz

Manual Data Exfiltration – Cloud Upload

Bitcoin Wallet Address  

bc1qkk8z69uxkrxdeuwlkvlk89p7qnr6cefa4aeq7p  

Leak Site  

hxxps://Darksidedxcftmqa[.]onion  


Complete advertisement from the Darkside group on a popular Russian hacking forum (Full translation from Russian to English)  

————- [Welcome to Darkside] ————–> Кто мы? ——————————  

Мы продукт нацеленный только на крупные корпорации. Можно детальнее прочесть тут: https://www.forbes.com/sites/daveywinder/2020/08/23/beware-of-the-dark-side-a-sinister-new-1-million-cybersecurity-threat-Darkside-ransomware/ https://bbc.com/news/technology-54591761https://www.wired.com/story/ransomware-gone-corporate-Darkside-where-will-it-end/ https://www.bleepingcomputer.com/news/security/Darkside-ransomware-hits-north-american-real-estate-developer/  

Кого мы ищем? 

 ——————————  

Ограниченное количество стабильных и адекватных партнеров, кто понимает зачем нужно выгружать данные, что такое бэкапы и как их удалять, русскоговорящих, со средними выплатами от 400к. Кого мы НЕ ищем?  

—————————— 

 Англоговорящих личностей. 

  • Сомнительных личностей, сотрудников секретной службы и аналитиков ИБ компаний. 

  • Тех, кто ставит дедики и занимается деятельностью отличимой от поставки сетей. 

  • Любые темы и предложения отличимые от этого поста. 

  • Желающих обучиться пентестингу и зарабатывать миллионы. 

  • Любителей ставить 100кк выкупа за 3.5 сервера. 

О софте? 

—————————— 

Мы готовы предоставить партнерам: 

  • Windows [full ASM, salsa20 + rsa 1024, i/o, собственная реализация salsa и rsa, fast / auto (улучшенный space) / full, имперсонализация токена для работы с шарами, раб столом, освобождение занятых файлов, изменение прав на файлы, arp scanner, завершения процессов, сервисов, drag-and-drop и много другого]. 

  • Linux [C++, chacha20 + rsa 4096, многопоточен (в том числе Hyper-threading, аналог i/o на windows), поддержка урезанных сборок ос (esxi 5.0+), fast / space, настройка каталогов и много другого]. 

  • Админ панель [full ajax, автоматический прием Bitcoin, Monero, генерация win / lin билдов с указанием всех параметров (процессы, сервисы, папки, расширения…), отстук ботов и детальная статистика по результативности компании, автоматическое распределение и вывод средств, саб–аккаунты, онлайн чат и множество другого]. 

  • Leak site [скрытые посты, поэтапная публикация данных таргета и еще множество функционала]. 

Все решения уже проверены и доделаны, мы сами работаем своим софтом и не писали его на продажу / аренду, в отличие от многих продуктов.То чего нам не хватало в работе с другими партнерскими программами — мы реализовали у себя.
Правила? 

—————————— 

  • Следующие сферы запрещены:
    – Медицина (Больницы, госпитали).
    – Образование (Университеты, школы).
    – Государственный сектор (муниципалитеты, любые гос органы).
    – Некоммерческие организации (благотворительные фонды, ассоциации). 

  • Запрещены любые действия, которые наносят репутационный урон имиджу продукта. 

  • Запрещена любая работа по СНГ (в том числе Грузии, Украине). 

  • Запрещена передача аккаунта третьим лицами. 

Какой процент? 

——————————  

От 25% до 10%. В софте динамическая система рейта. Чем больше выплата, тем меньше % партнерки и наоборот.Так же возможен стабильный рейт, это обсуждается. Как попасть?  

—————————— 

 Пройти собеседование, показать свою работу и выплаты, ответить на необходимые вопросы.Но для начала написать в ЛС. При этом указать: 

  • Свой опыт работы. 

  • С какими партнерскими программами работали. 

  • Диапазон сумм выкупа. Минимум, максимум, средняя. 

  • Работаете сами или в команде. 

  • TOX или jabber. 

Если вам не ответили, то вы не подошли, спамить в теме не нужно. 

Рассматриваем ли мы доступы в сети? 

——————————  

Да, USA от 400kk, с предложениями можно отписать в ЛС, написав сайт, сферу деятельности компании и контакт. Если компания интересна – с вами свяжутся. Какие гарантии?  

——————————  

Депозит в 20 BTC (~305k на момент написания) на xss.is. Если у вас будут супер предложения, мы с удовольствием его поднимем, вплоть до 1кк и более. 

Translation to English: 

Who are we looking for? 

 ——————————  

A limited number of stable and adequate partners who understand the importance of exfiltrating data, awareness of backups and how to delete them, Russian-speaking, with average payouts of 400k.  

Who are we NOT looking for?  

—————————— 

  • English-speaking personalities. 

  • Suspicious individuals, employees of the secret service and analysts of information security companies. 

  • Those who only setup RDP access or do other things other than deploy on networks. 

  • Any topics and suggestions different from this post. 

  • Those who want to learn pen-testing and earn millions. 

  • Those who think they can demand US$100M in ransom for 3.5 servers. About software? 

——————————  

We are ready to provide partners with:  

  • Windows payloads [full ASM (assembly language), I/O, custom implementation of the Salsa20 and RSA-1024 ciphers, fast / automated / full encryption, token impersonation for accessing shared network drives, process termination to encrypt open files, file permission modification, ARP scanning tool, the drag-and-drop UI/UX features, and much more) 

  • Linux payloads [C++, ChaCha20 + RSA-4096, multithreading (including hyper-threading, an analogue of the Windows I/O system), support of stripped-down OS versions (ESXI 5.0 and up), fast [encryption] / space [overwrite], catalog adjustment, and many other things]. 

  • Admin panel [ajax, automatic transaction processing for Bitcoin, Monero, generation of Windows/Linux builds with selectable parameters (processes, services, folders, and extensions), bots will report detailed statistics on the company’s performance, ability to create sub-accounts, online chat and much more]. 

  • Leak site [ability to hide posts, allows for detailed disclosures of compromised data, and much more]. All solutions have been tested and we work with our own software and did we did not produce it simply for sale/rent, unlike many products. In our program, we’ve implemented everything we wanted, but did not find in other affiliate programs. 

Rules? 

 ——————————  

  1. The following areas are prohibited: 

  • Healthcare (clinics and hospitals).  

  • Education (universities and schools).  

  • The public sector (municipal services and public agencies).  

  • Non-profit organizations (charitable foundations and associations).  

Any actions that can damage the product reputation are prohibited.  

Do not target systems in the CIS (this includes Georgia and Ukraine).  

Sharing accounts is not allowed.  

What’s the percentage/share of profits?  

——————————  

From 25% to 10%. The software has a dynamic rate system. The higher the payout, the lower the% of the affiliate program and vice versa.  

A stable rate is also possible, this is being discussed.  

How to get?  

——————————  

Pass an interview, show your work and payments, answer the necessary questions. First, send us a message. Indicate:  

  • Your previous experience. 

  • What other programs you’ve worked.

  • Your range of previous closed payments; minimum, maximum, average. 

  • Your preferences on working alone or with a team. 

  • Provide your TOX or Jabber contact. 

If we don’t answer you, then you weren’t the right fit, don’t spam us about it in the topic thread. Will we consider network accesses?  

——————————  

Sure, provided it’s a U.S. company with US$400M+ in revenue.  

Solicit your offer for consideration; provide company website, line of business, and your contact details. If we’re interested, we’ll contact you.  

What guarantees?  

——————————  

We made a deposit of 20 BTC (~ 305,000 USD) with forum escrow at XSS. If you make an awesome partnership proposal, we may raise that deposit to 1M+ to instill further confidence.  

——————————   

Note: Edited for clarity and readability 

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Article

Critical MOVEit Automation Vulnerabilities Disclosed

A security advisory released by Progress Software details critical and high-severity vulnerabilities affecting their MOVEit Automation managed file transfer (MFT) solution. The vulnerabilities, tracked as CVE-2026-4670 and CVE-2026-5174, could allow a threat actor to bypass authentication and escalate privileges, leading to unauthorized access, administrative control, and data exposure. Cybercriminals have leveraged several MFT tools in previous campaigns, including the Accellion File Transfer Application (FTA), Fortra GoAnywhere MFT, and Cleo MFT. Flaws in MFT software are highly targeted by cybercriminals due to the volume and sensitivity of the data they control. 

What’s Notable and Unique

  • MOVEit Transfer was heavily exploited by the Cl0p ransomware group in the summer of 2023. While the window of exploit activity lasted only a few weeks, victim extortion and data leaks continued throughout the remainder of the year, leading to more than 70 class-action lawsuits filed in the U.S.

  • There is no workaround or hotfix for these vulnerabilities. To fully patch the flaws, MOVEit administrators need to perform a "full install" of the latest version, which will require taking the system offline.

  • Security researchers have discovered ~1,400 MOVEit Automation instances exposed to the internet, with dozens belonging to U.S. local and state government agencies.

Analyst Comments

While the vulnerabilities patched in Progress Software's recent release differ from the SQL injection vulnerability exploited by the Cl0p ransomware group in 2023, exploitation of CVE-2026-4670 and CVE-2026-5174 could lead to equally impactful outcomes. Beyond the immediate impacts on affected organizations, trusted data-exchange platforms provide threat actors with an avenue to obtain sensitive information and infect partner and supplier environments. Furthermore, Arete has seen the time window between disclosure and weaponization of critical vulnerabilities continue to shrink, especially as threat actors increasingly adopt AI-enabled tooling. As such, organizations should not only implement the patches released by Progress Software, but also hunt for typical post-compromise behavior like enumeration of the underlying database, the creation of new user accounts or users operating with unexpected administrator privileges, and the presence of unauthorized remote monitoring and management (RMM) tools. 

Sources

  • MOVEit Automation Critical Security Alert Bulletin – April 2026 – (CVE-2026-4670, CVE-2026-5174) 

  • From Breach to Courtroom: Inside the MOVEit Exploitation and Mass Litigation 

  • Progress warns of critical MOVEit Automation auth bypass flaw 

A graphic with futuristic lines showing a text saying Ransomware Trends and Data Insights, a monthly blog post.
A graphic with futuristic lines showing a text saying Ransomware Trends and Data Insights, a monthly blog post.

Article

Ransomware Trends & Data Insights: April 2026

The threat landscape has remained relatively predictable thus far in 2026. In April, Qilin dethroned Akira as the most active threat group for the month. Akira, who had been the top ransomware threat each month since July 2025, was still only slightly behind Qilin and had roughly the same activity level as in March. INC Ransom and DragonForce also remained active threats in April, with those four ransomware groups accounting for half of all ransomware and extortion activity observed by Arete.

A monthly graph showing the latest threat actor accounting for half of all ransomware and extortion acitivty observed by Arete.

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

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

  • Multiple ransomware operations continue to leverage the Bring Your Own Vulnerable Driver (BYOVD) technique to disable endpoint security controls prior to ransomware deployment. Qilin has recently been observed leveraging a malicious file loaded via DLL side-loading along with vulnerable drivers, including rwdrv.sys and hlpdrv.sys, to gain kernel-level access and disable security processes. Arete observed Akira using the same vulnerable drivers in multiple engagements dating back to Q3 2025.


  • DragonForce has leveraged several of the same tools in recent engagements, including the remote desktop application Remotely Agent and the PoisonX.sys vulnerable driver. Additionally, open-source reporting indicates that the group recently used a Python-based backdoor known as VIPERTUNNEL to maintain reliable operator access and evade detection. DragonForce was responsible for over 7% of Arete ransomware engagements in April, and Arete notes increased activity from the group this year compared to 2025.


  • A social engineering tactic has reemerged in recent months in which threat actors impersonate IT and helpdesk staff via Microsoft Teams to contact employees and attempt to convince them to install remote access tools like Quick Assist, giving the threat actors remote access to the victim’s environment. This tactic was initially observed in late 2024 and early 2025 and was linked to now-defunct groups like Black Basta and Cactus, but has more recently been observed in intrusions linked to the Akira and Payouts King ransomware groups.

Sources

  • Arete Internal

Article

Payouts King Utilizes QEMU Emulator to Bypass EDR

Researchers recently identified threat actor campaigns leveraging QEMU, a free open-source virtual machine (VM) emulator, to evade endpoint security solutions. Since QEMU acts as a VM within the target environment, endpoint detection tools cannot scan inside the emulator or detect any malicious files or payloads QEMU contains. Although threat actors have been utilizing QEMU maliciously since 2020, recent activity is attributed to the Payouts King ransomware group and a cluster of threat actors believed to be initial access brokers who have also been exploiting the CitrixBleed2 vulnerability CVE-2025-5777.

What’s Notable and Unique

  • Payouts King has been observed deploying QEMU since November and uses the VM to create a reverse SSH backdoor to evade detection and install various tools, including Rclone, Chisel, and BusyBox.

  • In a separate campaign, threat actors are exploiting CVE-2025-5777, a Citrix NetScaler vulnerability that allows attackers to bypass authentication. Once they’ve gained initial access, the threat actors use QEMU to deploy tools inside the VM, which are then used to steal credentials, identify Kerberos usernames, perform Active Directory reconnaissance, and set up FTP servers for staging or data exfiltration.

Analyst Comments

Threat actors continue to focus their efforts on defense evasion, often leveraging legitimate, easily accessible tools such as QEMU. The continued use of QEMU by multiple threat actors highlights the effectiveness of these tactics and the difficulty in detecting and defending against them. To counter this campaign, organizations should proactively monitor for unauthorized QEMU installations, abnormal scheduled tasks, and port forwarding rules. 

 Sources

  • QEMU abused to evade detection and enable ransomware delivery

Article

Microsoft Teams Continues to be Leveraged in Social Engineering Attacks

Microsoft warns that threat actors are increasingly abusing Microsoft Teams and relying on legitimate tools to gain access and conduct lateral movement within enterprise networks. The threat actors impersonate IT or helpdesk staff to contact employees via cross-tenant chats and trick them into granting remote access for data theft. Microsoft has observed multiple intrusions with a similar attack chain that utilized commercial remote management software, like Quick Assist and the Rclone utility, to transfer files to an external cloud storage service. This tactic, notably associated with Black Basta and Cactus ransomware operations in late 2024 and early 2025, appears to have resurfaced, with similar activity more recently observed in intrusions linked to the Akira and Payouts King ransomware groups.

What’s Notable and Unique

  • Initial access is achieved by leveraging external collaboration features in Microsoft Teams to allow impersonation of internal support personnel, tricking users into bypassing security warnings. This reflects abuse of legitimate functionality rather than exploitation of a Microsoft Teams vulnerability.


  • Following initial access, attackers conduct rapid reconnaissance using Command Prompt and PowerShell to assess privileges, domain membership, and opportunities for lateral movement. Persistence is maintained through Windows Registry modifications, after which attackers leveraged WinRM for lateral movement, targeting domain-joined systems and high-value assets, including domain controllers.


  • Malicious payloads were staged in user-writable directories and executed through DLL side-loading via trusted, signed applications, enabling covert code execution while blending with legitimate activity. Additional remote management tools were also deployed to support broader access, while Rclone or similar utilities were used to stage and exfiltrate sensitive data to external cloud storage. 

Analyst Comments

This activity highlights how modern threat actors can leverage trusted collaboration workflows, remote management tools, and stealthy exfiltration techniques to conduct intrusions through a combination of social engineering and misuse of legitimate functionality. Effective defense depends on layered mitigations that combine identity controls, restricted remote administration, endpoint hardening, network protections, and user awareness measures to disrupt attacker activity at multiple stages of the intrusion lifecycle. To mitigate the risk of this and similar campaigns, users should treat external Teams contacts as untrusted by default, and administrators should restrict or closely monitor remote assistance tools while limiting WinRM usage to controlled systems. 

Sources

  • Cross‑tenant helpdesk impersonation to data exfiltration: A human-operated intrusion playbook

  • Microsoft: Teams increasingly abused in helpdesk impersonation attacks

  • Payouts King Takes Aim at the Ransomware Throne