Article
Threat Actors Turn to Supply Chain Attacks to Push Malware
Arete Analysis
Cyber Threats
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
Back to Blog Posts
Report
Arete's 2025 Annual Crimeware Report
Harness Arete’s unique data and expertise on extortion and ransomware to inform your response to the evolving threat landscape.
Article
FortiGate Exploits Enable Network Breaches and Credential Theft
A recent security report indicates that threat actors are actively exploiting FortiGate Next-Generation Firewall (NGFW) appliances as initial access vectors to compromise enterprise networks. The activity leverages recently disclosed vulnerabilities or weak credentials to gain unauthorized access and extract configuration files, which often contain sensitive information, including service account credentials and detailed network topology data.
Analysis of these incidents shows significant variation in attacker dwell time, ranging from immediate lateral movement to delays of up to two months post-compromise. Since these appliances often integrate with authentication systems such as Active Directory and Lightweight Directory Access Protocol (LDAP), their compromise can grant attackers extensive access, substantially increasing the risk of widespread network intrusion and data exposure.
What’s Notable and Unique
The activity involves the exploitation of recently disclosed security vulnerabilities, including CVE-2025-59718, CVE-2025-59719, and CVE-2026-24858, or weak credentials, allowing attackers to gain administrative access, extract configuration files, and obtain service account credentials and network topology information.
In one observed incident, attackers created a FortiGate admin account with unrestricted firewall rules and maintained access over time, consistent with initial access broker activity. After a couple of months, threat actors extracted and decrypted LDAP credentials to compromise Active Directory.
In another case, attackers moved from FortiGate access to deploying remote access tools, including Pulseway and MeshAgent, while also utilizing cloud infrastructure such as Google Cloud Storage and Amazon Web Services (AWS).
Analyst Comments
Arete has identified multiple instances of Fortinet device exploitation for initial access, involving various threat actors, with the Qilin ransomware group notably leveraging Fortinet device exploits. Given their integration with systems like Active Directory, NGFW appliances remain high-value targets for both state-aligned and financially motivated actors. In parallel, Arete has observed recent dark web activity involving leaked FortiGate VPN access, further highlighting the expanding risk landscape. This aligns with the recent reporting from Amazon Threat Intelligence, which identified large-scale compromises of FortiGate devices driven by exposed management ports and weak authentication, rather than vulnerability exploitation. Overall, these developments underscore the increasing focus on network edge devices as entry points, reinforcing the need for organizations to strengthen authentication, restrict external exposure, and address fundamental security gaps to mitigate the risk of widespread compromise.
Sources
FortiGate Edge Intrusions | Stolen Service Accounts Lead to Rogue Workstations and Deep AD Compromise
Article
Vulnerability Discovered in Anthropic’s Claude Code
Security researchers discovered two critical vulnerabilities in Anthropic's agentic AI coding tool, Claude Code. The vulnerabilities, tracked as CVE-2025-59536 and CVE-2026-21852, allowed attackers to achieve remote code execution and to compromise a victim's API credentials. The vulnerabilities exploit maliciously crafted repository configurations to circumvent control mechanisms. It should be noted that Anthropic worked closely with the security researchers throughout the process, and the bugs were patched before the research was published.
What’s Notable and Unique
The configuration files .claude/settings.json and .mcp.json were repurposed to execute malicious commands. Because the configurations could be applied immediately upon starting Claude Code, the commands ran before the user could deny permissions via a dialogue prompt, or they bypassed the authentication prompt altogether.
.claude/settings.json also defines the endpoint for all Claude Code API communications. By replacing the default localhost URL with a URL they own, an attacker could redirect traffic to infrastructure they control. Critically, the authentication traffic generated upon starting Claude Code included the user's full Anthropic API key in plain text and was sent before the user could interact with the trust dialogue.
Restrictive permissions on sensitive files could be bypassed by simply prompting Claude Code to create a copy of the file's contents, which did not inherit the original file's permissions. A threat actor using a stolen API key could gain complete read and write access to all files within a workspace.
Analyst Comments
The vulnerabilities and attack paths detailed in the research illustrate the double-edged nature of AI tools. The speed, scale, and convenience characteristics that make AI tools attractive to developer teams also benefit threat actors who use them for nefarious purposes. Defenders should expect adversaries to continue seeking ways to exploit configurations and orchestration logic to increase the impact of their attacks. Organizations planning to implement AI development tools should prioritize AI supply-chain hygiene and CI/CD hardening practices.
Sources
Caught in the Hook: RCE and API Token Exfiltration Through Claude Code Project Files | CVE-2025-59536 | CVE-2026-21852
Article
Ransomware Trends & Data Insights: February 2026
After a slight lull in January, Akira and Qilin returned to dominating ransomware activity in February, collectively accounting for almost half of all engagements that month. The rest of the threat landscape remained relatively diverse, with a mix of persistent threats like INC and PLAY, older groups like Cl0p and LockBit, and newer groups like BravoX and Payouts King. Given current trends, the first quarter of 2026 will likely remain relatively predictable, with the top groups from the second half of 2025 continuing to operate at fairly consistent levels month to month.
Figure 1. Activity from the top 5 threat groups in February 2026
Throughout the month of February, analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities:
In February, Arete observed Qilin actively targeting WatchGuard Firebox devices, especially those vulnerable to CVE-2025-14733, to gain initial access to victim environments. CVE-2025-14733 is a critical vulnerability in WatchGuard Fireware OS that allows a remote, unauthenticated threat actor to execute arbitrary code. In addition to upgrading WatchGuard devices to the latest Firebox OS version, which patches the bug, administrators are urged to rotate all shared secrets on affected devices that may have been compromised and may be used in future campaigns.
Reports from February suggest that threat actors are increasingly exploring AI-enabled tools and services to scale malicious activities, demonstrating how generative AI is being integrated into both espionage and financially motivated threat operations. The Google Threat Intelligence Group indicated that 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. Separate reporting from Amazon Threat Intelligence identified a threat actor leveraging commercially available generative AI services to conduct a large-scale campaign against FortiGate firewalls, gaining access through weak or reused credentials protected only by single-factor authentication.
The Interlock ransomware group recently introduced a custom process-termination utility called “Hotta Killer,” designed to disable endpoint detection and response solutions during active intrusions. This tool exploits a zero-day vulnerability (CVE-2025-61155) in a gaming anti-cheat driver, marking a significant adaptation in the group’s operations against security tools like FortiEDR. Arete is actively monitoring this activity, which highlights the growing trend of Bring Your Own Vulnerable Driver (BYOVD) attacks, in which threat actors exploit legitimate, signed drivers to bypass and disable endpoint security controls.
Sources
Arete Internal