Article
Ransomware Realities: Additional Risks During the Crisis
Arete Analysis
Cybersecurity Trends
Upon identification of a ransomware incident, many individuals may experience some level of stress or panic. However, while minimizing business interruption by restoring data from backups or other means, other post-incident factors must be considered so organizations can take proper precautions and avoid further security compromises.
Three’s a Crowd – Having Multiple Actors in Your Environment
In rare cases, continued use of initial access brokers (IABs) by ransomware groups can lead to multiple threat actors within an environment simultaneously. IABs sometimes sell the same access to multiple actors to increase profits, leading to re-encryption of the environment or, in some cases, multi-encryption events from multiple ransomware executables. Unsurprisingly, recovery in these scenarios is extremely difficult.
Malvertising is another way multiple actors can inadvertently end up within a victim’s environment. Malvertising is a malicious attack that involves injecting code into a legitimate advertising site. Various threat actors operate campaigns where they distribute backdoored or otherwise malicious versions of commonly used information security tools like Putty and WinSCP. When a victim downloads these tools, they may give the threat actors access to the environment, leading to threats as serious as ransomware. However, some threat actors also use simple Google searches to find and download legitimate tools they abuse to facilitate their operations. In some cases, threat actors may accidentally download an application backdoored by a different threat actor, meaning two threat actors are now operational within the victim environment.
The threat of having multiple actors within any given network demonstrates the importance of proper forensic analysis and top-tier endpoint detection and response (EDR) deployment following a security incident. Whether an organization chooses to recover from backups or pay for decryption, it is imperative that incident response companies can acquire adequate logs surrounding the time of the incident to conduct their analysis. Failure to do so can lead to increased costs associated with analysis, gaps in the timeline, and in the worst-case scenario, threat actors maintaining persistence in the victim environment, leading to events such as re-encryption.
Non-Reputable Companies and Software
In the critical moments following the identification of a ransomware incident, an overwhelming number of choices must be made. Ideally, the victim organization has a detailed incident response plan, practiced it several times in mock engagements, and printed out the plan in several physical locations which can be enacted with calm and purpose during the incident to decrease frenzy surrounding decision making. Of the many decisions to be made during the incident response process, one of the most important is choosing which organizations to partner with in the legal and recovery efforts. Pre-selection of data privacy counsel specializing in these events and a digital forensic incident response company are ideal, but not typically the case.
In cases where a ransom payment is required, most organizations will enlist a third-party organization registered as a money service business (MSB) to facilitate the ransom payment. The use of an unregistered third-party leads to higher organizational risks surrounding ransom payments, including potential regulatory action and the possibility of losing the ransom fund itself to a scam or otherwise, necessitating a second payment sum.
Additionally, when receiving a decryptor, whether from a third-party resource or a threat actor, the decryptor should be validated to ensure there are no hidden malicious functions. If a commercial decryptor is not properly vetted prior to being used to decrypt the victim’s more valuable files, it could lead to the inability to recover the files.
Conclusion
The best precaution against ancillary threats following a ransomware incident is an existing and tested incident response plan and immediate implementation of the remediation instructions provided by reputable vendors retained to respond to the incident. From increased security to financial risks, an organization’s choices following an incident can have a lasting impact on their ability to recover successfully.
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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.
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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