Article

Threat Actors Turn to Supply Chain Attacks to Push Malware

Sep 15, 2025

Arete Analysis

Cyber Threats

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.

Arete has observed multiple campaigns of targeted supply chain attacks in which threat actors convince targets to download malware disguised as legitimate software. The tactics displayed are similar throughout the campaigns, regardless of who is launching the attack or what malware is to be downloaded.

Targeting Developers

Nx, an open-source platform designed to manage codebases, experienced a security incident beginning on August 26th that allowed threat actors to publish malicious versions of npm packages and other tools. When unsuspecting developers download and execute the malicious package, the malware can scan the file system, collect credentials, and then post the information to a GitHub repo under the user’s account. It is estimated that at least 1,000 GitHub tokens were leaked, with 90% remaining valid, in addition to legitimate cloud credentials and npm tokens. During these attacks, the malware was typically run on developers’ machines using the Nx Visual Studio Code extension.

Following the remediation of the first incident, there were second and third rounds of this activity by threat actors on the Nx platform, leading to the compromise of additional GitHub auth tokens, cloud-based credentials, and other stolen information that actors could use to launch ancillary attacks. To combat this activity, Nx is removing malicious npm packages as they are identified and working to fix the root cause of the incidents. Nx recommends that users who have encountered malicious repositories assume they have been compromised, stop using the malicious packages, and check for file names. zshrc and .bashrc for any evidence of unfamiliar instructions before removal of the files.

Targeting Crypto Users

Threat actors are distributing malware targeting crypto users through smart contracts on the Ethereum blockchain. A smart contract is a piece of code that sits on the blockchain and automatically executes once the predefined parameters are met and mined into the blockchain. Threat actors abused this native capability by disguising malware as legitimate npm packages to be downloaded by unsuspecting users and used as smart contracts. Once the package is used in a contract, the malicious script runs, executing a malicious command that contacts the threat actors’ command and control (C2) server and can then download additional malware.

What’s unique in this instance is the method of downloading the malware. Typically, malicious packages download second-stage malware by using a script already contained within the package. This gives security-minded users the chance to identify the package’s nefarious purposes by scanning for unusual URLs or commands. However, by using smart contracts to host the URLs where these malicious commands are located, threat actors can improve their odds of evading detection.

One Off or Here to Stay?

These are just two recent and novel examples of supply chain attacks utilizing illegitimate npm packages, and there are always new nefarious npm packages being uploaded to code repository sites like Nx and GitHub. Tricking users into downloading malicious code is a simple way to deploy second-stage malware to unknowing individuals, especially developers who may have admin access to organizations and sensitive tooling. This access allows threat actors to immediately begin ancillary actions without escalating privileges within the environment.

Conclusion and Remediations

Combating the use of malicious npm packages by threat actors can be difficult in organizational settings. Developers should carefully assess each library they implement before deploying it to their organization. As discussed in this article, scanning packages for threats can help identify malicious code, actor-owned C2s, or other suspicious activity, but it isn’t foolproof. Additionally, developers should view code repositories through the lens of monitoring for social engineering attacks. Threat actors can “prop up” their repositories with likes and comments from other fake accounts to bump them towards the top of the repository list. Finally, anytime suspicious activity is suspected from a downloaded npm package, security teams should delete the files and reset passwords.

Sources

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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

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