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US Sanctions Grinex Crypto Exchange

Arete Analysis

Cybersecurity Trends

On August 14, 2025, the US Treasury Department announced sanctions against the spiritual successor to Garantex, the Grinex crypto exchange. Following law enforcement action against Garantex in March 2025, Grinex was created by Garantex employees to support sanctions evasion efforts. Subsequently, Grinex has become a hot spot for illicitly obtained funds from ransomware, extortion, and other fraudulent activities.

Multi-Step Process

The disruptions of Grinex and Garantex took years to execute and occurred over multiple phases of sanctions and law enforcement actions.

Phase 1 – Initial Sanctions against Garantex
In April 2022, the US Treasury Department sanctioned Estonia-based crypto exchange Garantex. This came after Estonia revoked Garantex’s license in February 2022 due to a lack of anti-money laundering/know-your-customer (AML/KYC) policies. At the time of the sanctions announcement, the Office of Foreign Assets Control (OFAC) assessed Garantex to have facilitated more than $100 million USD in illicit transactions. Interestingly, these sanctions did not inhibit Garantex from continuing their operations in providing cover for criminals and sanctioned customers of the exchange.

However, the sanctions did impact the ransomware landscape. Previously used by big-name ransomware groups such as Conti, LockBit, and Ryuk, the exchange was largely no longer a viable option for groups hoping to stay in business and evade additional law enforcement scrutiny. Groups that continued to utilize the sanctioned exchange or decided to use it later often earned themselves a one-way ticket to organizations’ no-pay lists and became a target for future law enforcement takedowns. Notably, 8Base ransomware was added to Arete’s internal no-pay list in September 2023 following an identified transaction to Garantex. 8Base was then taken down by a law enforcement action in February of 2025.

Phase 2 – Law Enforcement Attempts to Dismantle Garantex
Fast-forward to March 2025, when law enforcement agencies led by the US Secret Service attempted to disrupt the sanctioned crypto exchange by seizing Garantex’s primary domain and over $26 million in cryptocurrency assets. Unfortunately, the operation didn’t entirely disrupt the exchange and led to the unveiling of Grinex, often referred to as Garantex 2.0, later that month. Grinex began serving as the nefarious new arm of Garantex, and operators almost immediately began routing illicit funds through the new exchange.

Phase 3 – US Treasury Sanctions Grinex
This brings us to August 14th, when the US Treasury announced sanctions against the newly formed Grinex crypto exchange, three Garantex executives, and the A7A5 stablecoin, which is discussed in the next section. Currently, Grinex remains operational, and Arete is monitoring for use of the exchange as part of ransomware groups money laundering efforts.

But Wait, There’s More

The A7A5 stablecoin cryptocurrency is designed to track 1:1 with the Russian Ruble and appeared to be transferring funds from Garantex in January 2025, indicating the desire to create a sanction-resistant asset even before the disruption. The A7A5 coin, launched behind a veil of shell companies based in Kyrgyzstan, was adopted as an efficient sanctions evasion tool for individuals looking to cash out their illicitly obtained funds.

Analyst Comments

The identification and subsequent sanctions of Grinex and the A7A5 stablecoin significantly impinge upon cybercriminals’ ability to launder funds. Sanctions announcements especially impact ransomware groups, as many incident response firms, especially ones registered as money services businesses (MSBs), will not facilitate payments to groups using sanctioned infrastructure. The unsealing of indictments against the Garantex leadership and increased spotlight on the use of the A7A5 stable coin as a sanctions evasion tool allow organizations additional opportunities to monitor sanctions exposure and prohibit funds from moving to sanctioned entities. Arete cautions that new money laundering techniques designed to evade sanctions are likely to emerge in the future as cybercriminals continuously evolve their tactics in this space.

Sources

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Red alert symbols and warning icons spreading across a digital network, representing firewall compromise and widespread cyber intrusion.
Red alert symbols and warning icons spreading across a digital network, representing firewall compromise and widespread cyber intrusion.

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