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Fundamentals of Ransomware: What to Do Before and After Ransomware Strikes

Arete Analysis

By Raj Sivaraju

Amid the pandemic and as more people began working from home via unsecure networks, India saw a 31 percent rise in ransomware attacks.[i] What’s more, according to the Sophos “State of Ransomware 2020” study, of 300 Indian companies surveyed, 82 percent said they’d been hit by ransomware, with average ransom payments of approximately ₹80M.[ii]

Those numbers don’t bode well, especially as success is known to breed success. And don’t ransomware operators know it. There’s no reason for them to quit while they’re ahead — unless you give them one.

For now, the best way to combat this upward trend is to understand what you need to do before and after a ransomware attacks happens.

How to prepare: Get ready for ransomware before it strikes

Before a ransom note arrives and you see your business suddenly grind to a halt, there are actions you can take to limit your risk.

  • Get cyber insurance. Make sure you have cyber insurance. Ransomware attacks can get expensive fast — and for many, cyber insurance can be a business saver. Not only is there the extortion element to consider, but also the indirect costs of business disruption, reputational damage, data loss, data recovery, and potentially, diminished customer trust. Most regular insurance policies will not cover cyber risk exposure. So, speak to the experts and find out what your policy needs to keep you as safe and covered as possible.

  • Assess cybersecurity. If you aren’t already, start conducting annual audits and assessments of your environment so that you are aware of your company’s cybersecurity maturity and resilience levels, including potential security gaps.

  • Harden security posture. Consider deploying endpoint protection to all endpoints across your organization that could be potential gateways for malware attacks — there are some powerful endpoint detection and response (EDR) tools available on the market. Additionally, consider the latest technologies with behavioral artificial intelligence (AI) and fileless identification as well as containment tools.

  • Write an incident response plan and enlist assistance. Make sure to engage with a specialized third-party incident response vendor who not only will be on standby if an attack occurs but can also provide incident response preparedness training and design and guide you through tabletop exercises. Much like you would run fire drills in physical office spaces, it’s important to conduct simulation activities for incident response.

Dos and don’ts when ransomware hits

Now, let’s say you’ve been hit by ransomware. Here’s a checklist of what you should do — and of equal importance, what you should not do.

The dos:

  • Call your insurance carrier and third-party incident response vendor.

  • Remove infected systems from the network, take them offline.

  • Follow the instructions in the ransom note related to powering off systems.

  • Preserve all data from systems, firewalls, VPNs, proxy logs for forensic analysis.

  • Deploy advanced endpoint protection to all systems.

  • Dependent on organizational size, plan for a full return to normal operations to take up to two weeks.

The don’ts:

  • Do not panic. If you’ve done the pre-work and already set up your response teams, you can rest assured that they will react fast to triage, mitigate, negotiate, restore, all the things they’ve been trained to handle.

  • Do not shut down, power cycle, or reboot any infected systems.

  • Do not contact the threat actor yourself or try to negotiate. Leave this to your incident response vendor.

  • Do not wipe or re-image any systems as the forensic experts will need these for their investigation.

  • Do not rely on antivirus solutions, which failed to stop the ransomware.

  • Do not assume that once a decryptor is purchased that it’s all downhill from there.

Overview of Arete incident response

Arete has worked thousands of ransomware cases. When engaged, our incident response team focuses on getting your business back up and running as quickly as possible.

Step one is a scoping call to collect as many details as possible about the incident and begin collaborating with your insurance carrier to establish next steps for the investigation. Often, our incident response team will also be quick to deploy SentinelOne, an industry-leading EDR solution to clean and protect your environment — and help ensure that the threat actors do not re-encrypt systems after restoration.

If at any point you and your insurance carrier determine that paying a ransom is the most effective way to resolve the issue and return to normal business operations, our team will communicate with the bad actor on your behalf to negotiate a settlement.

With access regained, the team will assist in attack analysis and critical system restoration, bringing varied skill sets to deliver:

  • Data-driven security architecture review and recommendations.

  • Decryption and data recovery assistance.

  • IT infrastructure restoration and rebuilds.

  • Collection and preservation of forensic evidence.

  • Security improvements to limit or eliminate unauthorized access to networks, endpoints, and data.

Combined, these services can help you regain and maintain control of systems and assets, improve your cybersecurity going forward, and gather insights to prevent future incidents.

India’s unique opportunity: The time to get ahead of ransomware attacks is now

It’s time to be proactive. India is undergoing a digital transformation, which presents an opportunity to get ahead of this trend by educating employees, assessing security gaps, putting the right protections in place from the start, and having a clear and well-rehearsed incident response plan in place.

 

[i] Ransomware attacks rose by 31% amid pandemic: Report- The New Indian Express

[ii] sophos-the-state-of-ransomware-2020-wp.pdf

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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