Article
Law Enforcement Actions Leave ALPHV/BlackCat Scrambling to Salvage Operations
Dec 20, 2023
Cyber Threats
Threat Actors
Combating Ransomware

Through a coordinated law enforcement effort spearheaded by the FBI, ALPHV/BlackCat infrastructure was disrupted on December 7, 2023, in an operation publicly announced on December 19, 2023. After terrorizing businesses and organizations for over two years, the notorious ransomware group may have finally met its match.
What happened to BlackCat’s Infrastructure?
On December 7, 2023, the data leak website for ALPHV/BlackCat went offline and remained offline for more than 30 hours. This is one of the most prolonged disruptions the group has faced, as it previously only experienced periodic outages due to technical hosting issues. The BlackCat data leak site came back online with all data from previous victims removed before apparently being taken down for good on December 19, 2023, when existing BlackCat branding was replaced by an FBI banner including a TOR-based tip line for information on BlackCat and its affiliates.

Figure 1: Law Enforcement Seizure Banner Displayed on Known ALPHV/BlackCat Data Leak Sites on December 19, 2023
The BlackCat Decryptor
Prior to the takedown of BlackCat’s infrastructure, law enforcement maintained access to the threat actor’s environment for months and was able to obtain victim-specific decryption keys to BlackCat’s ransomware executable by monitoring the environment. The FBI used these decryption keys to offer decryption to 500 BlackCat victims as the FBI neared publicizing the takedown. The FBI estimated they were able to save organizations a total of $68 million in ransom demands.
However, based on Arete data, this is likely a conservative number. With an average initial ransom demand of $2.28 million in 2023, BlackCat demands observed by Arete are significantly higher than the demands calculated by law enforcement. While ransom payments are often significantly discounted from the original $2.28 million demand following a negotiation process, it is possible that this action taken by law enforcement could have saved victim organizations as much as five times as what was assessed by the FBI. Alternatively, the gap between Arete and the FBI’s estimated ransom payments may indicate how many organizations had either already paid a ransom before the decryption keys were available or were able to recover without paying the ransom.
The After-Action Report
While the initial data leak site (DLS) disruption nearly two weeks ago caused BlackCat’s operations to decrease significantly, three new victims were posted to the DLS between when the site came back online and when it was finally seized by the FBI. In one of those postings, BlackCat claimed to have reported a new victim to the Securities and Exchange Commission (SEC). In the intervening period, Arete also responded to a BlackCat engagement in which the threat actors utilized an old BlackCat encryptor. Therefore, while the infrastructure takedown certainly disrupted the scale and speed of BlackCat operations, it did not stop the operations of all affiliates.
Shortly after the FBI announced the website seizure on December 19, 2023, ALPHV/BlackCat’s operators stood up a new data leak site and claimed their website was “unseized.” Security researchers assess that BlackCat operators maintained access to the keys used to sign the original data leak site but lost access to their original servers. After standing up the new data leak site, BlackCat made a new post about a victim and stated they will no longer give victims additional time to conduct negotiations. The operators also stated they will harass executive teams and their children, report companies to the SEC and US Department of Health and Human Services (HHS), and release a clearnet (regular internet) link to data on victims.

Figure 2 ALPHV/BlackCat Post Excerpt Uploaded December 19, 2023
With a lack of trust in their own infrastructure, BlackCat affiliates began communicating with victims directly via email rather than relying on typical communication methods. While attempting to continue operations to the best of their ability, BlackCat operators reportedly later discovered that law enforcement gained access to a compromised domain controller and issued a concerning statement to their affiliates, giving them permission to “take the gloves off” in future operations.
The statement shared that all previously observed rules, minus the inability to target CIS* countries, no longer apply to BlackCat affiliates, and an increased percentage of ransom payments, now 90%, will go to affiliates. Additionally, several targets that were reportedly previously forbidden, such as hospitals and nuclear power plants, are now fair game for affiliates to target with the BlackCat encryptor. Finally, BlackCat stated they will no longer accept discounts from the original ransom demand. With an average negotiated discount of 63% off the original ransom demand observed by Arete, the inability to negotiate could cost BlackCat victims millions of dollars if they choose to make ransom payments.
Who is ALPHV/BlackCat?
ALPHV/BlackCat is a ransomware-as-a-service (RaaS) group that first emerged in November 2021. The group operates by providing ransomware software and infrastructure to other cybercriminals, who then use it to launch attacks on various targets. The group takes a cut of the ransom payments and leaks the stolen data of its victims on its Dark Web site. The group is also known for its unique extortion methods, which include reporting its victims to the SEC and creating false domains to impersonate victims and leak data.
Since its inception, ALPHV/BlackCat listed over 650 companies on its data leak site, making it one of the most prolific and dangerous ransomware groups active today. Throughout 2023, BlackCat was the most frequently observed ransomware group in Arete’s industry data. Among 56 different ransomware and extortion groups observed in 2023, BlackCat accounted for nearly a quarter of Arete’s overall engagements.

Figure 3: Visual from Arete’s Q3 2023 Crimeware Report
Affiliates of ALPHV/BlackCat include Scattered Spider, the ransomware group behind the brazen cyberattacks against MGM Resorts, Caesars, and more. The FBI and CISA issued a joint advisory about Scattered Spider in November 2023, warning of their use of ALPHV/BlackCat ransomware.
What are the implications of this takedown?
While the full implications of this takedown are currently unknown, it could have significant implications for the ransomware landscape. The takedown may disrupt the activities of many affiliates relying on ALPHV/BlackCat’s ransomware encryptor and infrastructure, likely forcing existing affiliates to move on to other ransomware programs or develop their own. Notably, LockBit ransomware quickly seized the opportunity to advertise that BlackCat affiliates could continue their current operations under LockBit’s RaaS operation. Additionally, this could lead to the emergence of new ransomware variants and groups, with affiliates bringing experience from previous programs. This happened before when law enforcement actions against other ransomware groups, such as DarkSide and REvil, resulted in the formation of new groups, like BlackMatter and Haron. Even before the FBI takedown, Arete observed a splintering of BlackCat affiliates, with groups like Scattered Spider conducting solo operations alongside operations using the BlackCat encryptor.
While the takedown of ALPHV/BlackCat’s websites is a positive development in the fight against ransomware, it is not a definitive victory. Ransomware remains a persistent and evolving threat that requires constant vigilance and collaboration from all stakeholders, including governments, businesses, and individuals.
BlackCat has been a widely impactful ransomware group, in part because it relied on affiliates with diverse means of compromising victims. Arete observed a wide variety of initial access measures in engagements involving ALPHV/BlackCat affiliates, including a sophisticated capability to exploit software and hardware vulnerabilities. Preventing BlackCat attacks and future ransomware attacks from affiliates that escape law enforcement requires a strong patch management program that prioritizes vulnerabilities with publicly released exploit code. Additionally, managing remote management tools in an environment is critical in preventing similar attacks. Arete identified third-party remote access tools as the initial intrusion method in more than eight percent of ALPHV/BlackCat engagements, but analysis of the full lifecycle of an ALPHV/BlackCat engagement showed those tools being used throughout the attacks to enable attacker operations. Neither method is unique to BlackCat operators and remains an important focus for defenders.
Footnotes
*The Commonwealth of Independent States (CIS) is a regional intergovernmental organization formed following the dissolution of the Soviet Union, including Russia, Belarus, Kazakhstan, Moldova, Armenia, Tajikistan, Uzbekistan, Kyrgyzstan, Azerbaijan, and Turkmenistan.
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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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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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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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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
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