Article

Avaddon Ransomware Hits AXA

May 28, 2021

Arete Analysis

Combating Ransomware

Endpoint Detection and Response

Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.

Summary  

Avaddon ransomware allegedly attacked European insurance provider AXA shortly after the company announced that it will stop paying ransoms for its clients. Our analysis provides an in-depth look at Avaddon’s tactics and recommended mitigations.

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From September 2020 to May 2021, Arete responded to nine Avaddon ransomware engagements across varying industry sectors, including professional services, financial services, healthcare, hospitality, public services, and retail.

During the first week of May, Arete received an FBI Liaison Alert System (FLASH) CU-000145-MW from the FBI Cyber Division. The Australian Cyber Security Center (ACSC) also released an alert about an ongoing Avaddon ransomware campaign.

According to reports, at the beginning of May 2021, AXA (one of Europe’s top five insurers) said it will stop reimbursing people in France who pay ransoms after cybercriminals target them with ransomware. It will also stop writing cyber insurance policies that cover customers for extortion payments to ransomware attackers. This decision is said to have come in response to concerns aired by French justice and cybersecurity officials during a recent senate roundtable in Paris about the global ransomware epidemic.

AXA has now found itself a victim of a ransomware breach. Public reports say that the Avaddon ransomware group has impacted AXA Asia Assistance IT operations in Thailand, Malaysia, Hong Kong, and the Philippines. The group claims to have stolen 3 terabytes of data, including ID cards, passport copies, customer claims, reserved agreements, denied reimbursements, payments to customers, contracts and reports, customer IDs, bank account scanned papers, hospital and doctor reserved material (private investigation for fraud), and customer medical reports, including HIV, hepatitis, STD, and other illness reports. According to reports, the ransomware group said AXA had 240 hours to communicate and cooperate or they would start leaking valuable company documents.

While the juxtaposition of the AXA decision to not pay ransoms for French victims or even write ransomware coverage in France could have motivated the attack, Arete has no information or evidence to link these events. In general, and as disclosed in publicly released news reports, attacks against insurance companies are increasing.

In a recent interview, a member of the REvil ransomware gang was asked if they target organizations with cyber insurance. His response:

“Yes, this is one of the tastiest morsels. Especially to hack the insurers first — to get their customer base and work in a targeted way from there. And after you go through the list, then hit the insurer themselves.”

- "Unknown" REvil Ransomware Representative

In its CU-000145-MW FLASH Alert, the FBI notified of activity by cyber actors using Avaddon ransomware-as-a-service (RaaS) to target U.S. and foreign private sector companies, manufacturing organizations, and healthcare agencies. The alert states that the threat actors:

  • Have compromised victims through remote access login credentials like remote desktop protocol (RDP) and virtual private network (VPN) with single-factor authentication or improperly configured RDP.

  • Once they gain access to a victim’s network, they map the network and identify backups for deletion and/or encryption. They use malware that escalates privileges, contains anti-analysis protection code, enables persistence on a victim system, and verifies the victim is not located in the Commonwealth of Independent States (CIS). Their ransomware terminates services and processes related to backup and antivirus running in system memory before encrypting victims’ data.

  • Encrypt and exfiltrate data from the victim network for extortion, threatening its release in their TOR leak site (avaddongun7rngel.onion) if victims don’t pay the ransom.

  • Will perform a 5% data leak if the ransom is not paid within three to five days and follow with a full leak of the data stolen if the ransom is not paid.

  • Announced in January 2021 that they would attack victims who do not pay ransoms with distributed denial-of-service (DDoS) attacks.

  • Have used the following IPs during RDP connections: 185.216.33.0/24, 45.145.67.0/23, 193.27.229.0/23, 217.8.117.63.

The ACSC report includes some of the following tactics, techniques, and procedures (TTPs):

  • Phishing and malicious email spam (malspam) campaigns to deliver malicious JavaScript files. These are often low in sophistication, containing a threat suggesting the attached file contains a compromising photo of the victim.

  • Using “double extortion” techniques as coercion and further pressure to pay a ransom, including:

    • Threatening to publish the victim’s data via the Avaddon Data Leak Site (DLS): avaddongun7rngel.onion.

    • Threatening the use of DDoS attacks against the victim (first identified in February 2021).

  • Identify the default geolocation and system language of the user’s device to determine whether the user will be targeted for attack or not.

  • Use of Windows Scheduled Task to establish persistence.

The report also includes the following information about countries and sectors affected by this threat:

Statistical Data on Avaddon Ransomware From Arete Metrics

The information listed is based on Avaddon cases investigated by Arete IR since September 2020. Our IR and Data Analytics practices work together to track key data points for every ransomware engagement, and our IR practice tracks data points on the ransomware variant and collects statistics based on handled engagements:  

  • Arete has responded to nine Avaddon breach response engagements since September 2020 in the following sectors: Professional Services | Financial Services | Healthcare | Hospitality | Public Services | Retail  

  • At victim/breach coach/carrier request, Arete negotiated and paid the ransom in four of the nine Avaddon cases. In the remaining five cases, we were able to assist the victim in recovering from backups.  

  • Average ransom demand: US$1,089,375.  

  • Maximum ransom demand: US$4,000,000. 

  • Minimum ransom demand: US$15,000.  

  • We observed data exfiltration in 67% of the incidents.  

  • Phishing emails and RDP were the methods of infection 60% of the time. 

During investigations, our incident responders have observed threat actors using RDP to remote into the victim environment. We have seen attackers use Mimikatz, Advanced Port Scanner, Advanced IP Scanner, PsExec, Rclone, Gmer, and svhost.exe. We have also seen exe_[victim_org].exe as the ransomware file names.

Mitigation Measures Recommended By The FBI and ACSC

  • Back up critical data offline.  

  • Ensure copies of critical data are in the cloud or on an external hard drive or storage device.  

  • Secure your backups and ensure data is not accessible for modification or deletion from the system where the data resides. 

  • Use two-factor authentication with strong passwords, including for remote access services.  

  • Monitor cyber threat reporting regarding the publication of compromised VPN login credentials and change passwords/settings, if applicable.  

  • Regularly change passwords to critical systems.  

  • Keep computers, devices, and applications patched and up to date.  

  • Install and regularly update antivirus or antimalware software on all hosts.  

  • Scan emails and attachments to detect and block malware.  

  • Implement a training program and processes to identify phishing and externally sourced emails.

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Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.
Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.

Article

Feb 20, 2026

Threat Actors Leveraging Gemini AI for All Attack Stages

State-backed threat actors are leveraging Google’s Gemini AI as a force multiplier to support all stages of the cyberattack lifecycle, from reconnaissance to post-compromise operations. According to the Google Threat Intelligence Group (GTIG), threat actors linked to the People’s Republic of China (PRC), Iran, North Korea, and other unattributed groups have misused Gemini to accelerate target profiling, synthesize open-source intelligence, identify official email addresses, map organizational structures, generate tailored phishing lures, translate content, conduct vulnerability testing, support coding tasks, and troubleshoot malware development. Cybercriminals are increasingly exploring AI-enabled tools and services to scale malicious activities, including social engineering campaigns such as ClickFix, demonstrating how generative AI is being integrated into both espionage and financially motivated threat operations. 

What’s Notable and Unique 

  • Threat actors are leveraging Gemini beyond basic reconnaissance, using it to generate polished, culturally nuanced phishing lures and sustain convincing multi-turn social engineering conversations that minimize traditional red flags.  

  • In addition, threat actors rely on Gemini for vulnerability research, malware debugging, code generation, command-and-control development, and technical troubleshooting, with PRC groups emphasizing automation and vulnerability analysis, Iranian actors focusing on social engineering and malware development, and North Korean actors prioritizing high-fidelity target profiling. 

  • Beyond direct operational support, adversaries have abused public generative AI platforms to host deceptive ClickFix instructions, tricking users into pasting malicious commands that deliver macOS variants of ATOMIC Stealer.  

  • AI is also being integrated directly into malware development workflows, as seen with CoinBait’s AI-assisted phishing kit capabilities and HonestCue’s use of the Gemini API to dynamically generate and execute in-memory C# payloads.  

  • Underground forums show strong demand for AI-powered offensive tools, with offerings like Xanthorox falsely marketed as custom AI but actually built on third-party commercial models integrated through open-source frameworks such as Crush, Hexstrike AI, LibreChat-AI, and Open WebUI, including Gemini. 

Analyst Comments 

The increasing misuse of generative AI platforms like Gemini highlights a rapidly evolving threat landscape in which state-backed and financially motivated actors leverage AI as a force multiplier for reconnaissance, phishing, malware development, and post-compromise operations. At the same time, large-scale model extraction attempts and API abuse demonstrate emerging risks to AI service integrity, intellectual property, and the broader AI-as-a-Service ecosystem. While these developments underscore the scalability and sophistication of AI-enabled threats, continued enforcement actions, strengthened safeguards, and proactive security testing by providers reflect ongoing efforts to mitigate abuse and adapt defenses in response to increasingly AI-driven adversaries. 

Sources 

  • GTIG AI Threat Tracker: Distillation, Experimentation, and (Continued) Integration of AI for Adversarial Use 

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Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.
Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.

Article

Feb 12, 2026

2025 VMware ESXi Vulnerability Exploited by Ransomware Groups

Ransomware groups are actively exploiting CVE‑2025‑22225, a VMware ESXi arbitrary write vulnerability that allows attackers to escape the VMX sandbox and gain kernel‑level access to the hypervisor. Although VMware (Broadcom) patched this flaw in March 2025, threat actors had already exploited it in the wild, and CISA recently confirmed that threat actors are exploiting CVE‑2025‑22225 in active campaigns.

What’s Notable and Unique

  • Chinese‑speaking threat actors abused this vulnerability at least a year before disclosure, via a compromised SonicWall VPN chain. 

  • Threat researchers have observed sophisticated exploit toolkits, possibly developed well before public disclosure, that chain this bug with others to achieve full VM escape. Evidence points to targeted activity, including exploitation via compromised VPN appliances and automated orchestrators.

  • Attackers with VMX level privileges can trigger a kernel write, break out of the sandbox, and compromise the ESXi host. Intrusions observed in December 2025 showed lateral movement, domain admin abuse, firewall rule manipulation, and staging of data for exfiltration. 

  • CISA has now added CVE-2025-22225 to its Known Exploited Vulnerabilities (KEV) catalog, underscoring ongoing use by ransomware attackers.

Analyst Comments

Compromise of ESXi hypervisors significantly amplifies operational impact, allowing access to and potential encryption of dozens of VMs simultaneously. Organizations running ESXi 7.x and 8.x remain at high risk if patches and mitigations have not been applied. Therefore, clients are recommended to apply VMware patches from VMSA‑2025‑0004 across all ESXi, Workstation, and Fusion deployments. Enterprises are advised to assess their setups in order to reduce risk, as protecting publicly accessible management interfaces is a fundamental security best practice.

Sources

  • CVE-2025-22225 in VMware ESXi now used in active ransomware attacks

  • The Great VM Escape: ESXi Exploitation in the Wild

  • VMSA-205-004: VMware ESXi, Workstation, and Fusion updates address multiple vulnerabilities (CVE-205-22224, CVE-2025-22225, CVE-2025-22226)

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Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.
Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.

Article

Feb 5, 2026

Ransomware Trends & Data Insights: January 2026

Although Akira was once again the most active ransomware group in January, the threat landscape was more evenly distributed than it was throughout most of 2025. In December 2025, the three most active threat groups accounted for 57% of all ransomware and extortion activity; in January, the top three accounted for just 34%. Akira’s dominance also decreased to levels more consistent with early 2025, as the group was responsible for almost a third of all attacks in December but just 17% in January. 

The number of unique ransomware and extortion groups observed in January increased slightly, to 17, up from 14 in December. It is too early to assess whether this trend will be the new normal for 2026. It is also worth noting that overall activity in January was lower than in previous months, consistent with what Arete typically observes at the beginning of a new year.

Figure 1. Activity from all threat groups in January 2026

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

  • In January, Arete observed the reemergence of the LockBit Ransomware-as-a-Service (RaaS) group, which deployed an updated “LockBit 5.0” variant of its ransomware. LockBit first announced the 5.0 version on the RAMP dark web forum in early September 2025, coinciding with the group’s six-year anniversary. The latest LockBit 5.0 variant has both Windows and Linux versions, with notable improvements, including anti-analysis features and unique 16-character extensions added to each encrypted file. However, it remains to be seen whether LockBit will return to consistent activity levels in 2026.

  • The ClickFix social engineering technique, which leverages fake error dialog boxes to deceive users into manually executing malicious PowerShell commands, continued to evolve in unique ways in January. One campaign reported in January involved fake Blue Screen of Death (BSOD) messages manipulating users into pasting attacker-controlled code. During the month, researchers also documented a separate campaign, dubbed “CrashFix,” that uses a malicious Chrome browser extension-based attack vector. It crashes the web browser, displays a message stating the browser had "stopped abnormally," and then prompts the victim to click a button that executes malicious commands.

  • Also in January, Fortinet confirmed that a new critical authentication vulnerability affecting its FortiGate devices is being actively exploited. The vulnerability, tracked as CVE-2026-24858, allows attackers with a FortiCloud account to log in to devices registered to other account owners due to an authentication bypass flaw in devices using FortiCloud single sign-on (SSO). This recent activity follows the exploitation of two other Fortinet SSO authentication flaws, CVE-2025-59718 and CVE-2025-59719, which were disclosed in December 2025.

Source

Arete Internal

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Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.
Red digital warning symbol glowing on a circuit board interface, representing active ransomware exploitation of the VMware ESXi CVE 2025 22225 vulnerability and hypervisor compromise.

Article

Feb 2, 2026

New FortiCloud SSO Vulnerability Exploited

Fortinet recently confirmed that its FortiGate devices are affected by a new critical authentication vulnerability that is being actively exploited. The vulnerability, tracked as CVE-2026-24858, allows attackers with a FortiCloud account to log in to devices registered to other account owners due to an authentication bypass flaw in devices using FortiCloud single sign-on (SSO). CISA added the vulnerability to its Known Exploited Vulnerabilities catalogue and gave federal agencies just three days to patch, which requires users to upgrade all devices running FortiOS, FortiManager, FortiAnalyzer, FortiProxy, and FortiWeb to fixed versions. This recent activity follows the exploitation of two other SSO authentication flaws, CVE-2025-59718 and CVE-2025-59719, which were disclosed last month.

What’s Notable and Unique

  • There are strong indications that much of the recent exploitation activity was automated, with attackers moving from initial access to account creation within seconds.

  • As observed in December 2025, the attackers’ primary target appears to be firewall configuration files, which contain a trove of information that can be leveraged in future operations.

  • The threat actors in this campaign favor innocuous, IT-themed email and account names, with malicious login activity originating from cloud-init@mail[.]io and cloud-noc@mail[.]io, while account names such as ‘secadmin’, ‘itadmin’, ‘audit’, and others are created for persistence and subsequent activity.

Analyst Comments

This is an active campaign, and the investigation into these attacks is ongoing. Organizations relying on FortiGate devices should remain extremely vigilant, even after following patching guidance. With threat actors circumventing authentication, it’s crucial to monitor for and alert on anomalous behavior within your environment, such as the unauthorized creation of admin accounts, the creation or modification of access policies, logins outside normal working hours, and anything that deviates from your security baseline.

Sources

  • Administrative FortiCloud SSO authentication bypass

  • Multiple Fortinet Products’ FortiCloud SSO Login Authentication Bypass

  • Arctic Wolf Observes Malicious Configuration Changes On Fortinet FortiGate Devices via SSO Accounts

  • Arctic Wolf Observes Malicious SSO Logins on FortiGate Devices Following Disclosure of CVE-2025-59718 and CVE-2025-59719

Read More