Article
Suspected North Korean Actors Pull off the Largest Crypto Heist in History
Arete Analysis
Threat Actors
On February 21st, 2025, approximately $1.4 billion USD in Ethereum was stolen from cryptocurrency exchange Bybit. Ethereum held a price of $2600 per token as of February 21st and is one of many cryptocurrencies the exchange holds. Some quick division shows that at least 500,000 Ethereum coins were stolen, making this the largest crypto heist to date in value. Both TRM Labs and Chainalysis have assessed the threat actor to be associated with North Korea with high confidence due to an overlap in crypto wallets tracked as belonging to North Korea.
What’s notable and unique?
North Korea has a long history of financial fraud, money laundering, and other illicit activity. Members of the Democratic People’s Republic of Korea (DPRK) military regularly participate in illicit activities, including remote worker fraud, cryptocurrency hijacking and mining, money mules, wire fraud, and even ransomware. These cybercriminal activities allow DPRK to bypass international sanctions to raise funds for their military.
The threat actors compromised one of Bybit’s offline cold wallets, digital wallets that store private keys needed to access other cryptocurrency wallets completely offline. Due to the wallet being disconnected from the internet, the most likely sources of the compromise were a supply chain attack, insider threat, or a private key compromise.
The alleged North Korean threat actors may not be able to fully monetize the theft. The funds must now be laundered before being taken out at another exchange, as most of the initial wallets to which funds were transferred have been marked as having stolen funds on legitimate cryptocurrency exchanges. The laundering will likely be a two-step process. First, the funds will be exchanged for a native cryptocurrency, such as Ether or BTC, as it is difficult to track stolen funds across cryptocurrency blockchain transfers. Next, the actors will attempt to cover their tracks further by layering the funds to throw investigators off their trail. Shortly after the compromise the actor used 50 wallets and placed 10,000 coins in each, further supporting the alleged theft of 500,000 coins in total.
Bybit has offered a 10% bounty on the stolen coins, leading to a potential purse of $140 million. So far, $42.89 million of the stolen funds have been frozen. However, it is unclear whether this is the work of bounty hunters, law enforcement, or Bybit.
Conclusion
While crypto-related attacks may seem like a new concept at face value, this is the most recent heist in a string traversing ten years. In 2024 alone, North Korean threat actors were associated with $1.5 billion out of $2.2 billion in theft. With North Korea conducting these thefts, the funds enter a broader cybercriminal ecosystem, increasingly invading the insurance ecosystem. Most recently, these threats have expanded into North Koreans fraudulently joining North American and European companies, stealing their source code, and then extorting the companies. Funds stolen in cryptocurrency thefts like the Bybit thefts are funding infrastructure supporting this increasingly stealthy form of extortion, consequently resulting in funds supporting the North Korean military.
Fortunately, as threat actors and money launderers strengthen their ability to hide stolen money, blockchain analytic techniques and toolsets have also evolved. Often, the best way to prevent crypto heists and cybercrime is to implement sound security principles, including password management, vulnerability patching, and end user training.
Sources
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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