How to Effectively Protect Your Business from Ransomware

What Is Ransomware and Why Are Businesses Targeted?

A ransomware attack is a type of malicious software that encrypts a system’s files and then demands a ransom to restore access. Some variants go further by exfiltrating sensitive information and threatening to publish it to increase pressure.

How Ransomware Spreads

Ransomware propagates through multiple known vectors, often mundane in a company’s daily digital life, such as:

• Phishing and malicious links in emails, instant messaging, or social networks.
• Infected attachments, even through documents that appear legitimate.
• RDP vulnerabilities.
• Infected USB drives or other removable devices introduced into the operating system without control.

In many cases, the initial attack exploits a known but unpatched security flaw—such as a vulnerability in a business application, hypervisor, or remote access gateway.

Why Both SMBs and Large Enterprises Are Vulnerable

All organization sizes are at risk. SMBs often lack the resources for monitoring and response, while large enterprises have an extended attack surface due to their complex environments.
The consequences go beyond technical damage—data exposure and reputational harm are also at stake.
To assess the scale of a breach, see our dedicated analysis: Data Breach: What to Do?

Focus on Economic and Legal Impact

A ransomware attack can lead to weeks of downtime, loss of critical data, reduced productivity, and contractual penalties.
Legally, the exposure of personal data triggers notification obligations—such as to the CNIL—alongside risks of administrative sanctions and legal disputes.
The total cost, direct and indirect, far exceeds the mere technical restoration.

The Different Forms of Ransomware

File Encryption

The classic scenario: data is encrypted, systems become unusable, and a ransom demand appears for a decryption key.

Double Extortion

Attackers combine encryption with data theft. Even with regular backups, they threaten to publish stolen information if the ransom is not paid.

Recent Attack Examples

• SonicWall reported a security incident illustrating why 2025 is the year to move beyond VPNs. The attack shows how poorly secured remote access becomes a prime entry point.
  
  
• Several European municipalities and hospitals experienced prolonged paralysis, impacting public services and making restoration complex.
  
  
• Industrial companies saw production lines halted—sometimes despite backups—due to corruption of system assets and directories.

How Ransomware Has Evolved

Modern ransomware no longer simply encrypts data—it targets the infrastructure itself.

Beyond Encryption

Some variants corrupt or destroy system file metadata, snapshots, or even hypervisors. As a result, recovery may be impossible even if the ransom is paid, nullifying any hope of a quick return to normal operations.

Attacks Capable of Paralyzing Entire Organizations

Operators map the infrastructure, exfiltrate secrets, neutralize security solutions, disable EDR, cut authentication, and spread the attack further.

Why Backups Are No Longer Enough

Attackers often target backup repositories, snapshots, and digital vaults first.
Effective ransomware protection now requires a multilayer approach combining prevention, isolation, segmentation, access control, logging, and continuous monitoring.

What Makes You a Potential Target?

• Obsolete devices or technology
  End-of-life servers, outdated software versions, unpatched networking equipment—all increase your attack surface.
• No backup plan for your data
  Without regular, tested, immutable backups, encryption can become an existential crisis.
• Outdated operating system
  Irregular updates, delayed patches, and untracked components leave published vulnerabilities open.
• No cybersecurity plan
  Without governance, access control, logging, detection, and response, even simple alerts may go unnoticed.

Best Practices to Prevent Ransomware

The key is to combine human, procedural, and technical measures.

Train Employees in Cybersecurity

• Regular, role-specific training to spot malicious links and subtle warning signs.
• Phishing simulations to measure and improve real-world resilience.
• Everyday best practices:
  
  • Avoid opening unexpected emails.

• • Verify the sender’s domain.

• • Avoid clicking suspicious attachments.

• • Never plug in an unknown USB drive.

• • Report suspicious behavior immediately.
    
    

Back Up Data Regularly

• Importance: Define realistic RTO/RPO objectives and classify critical data.
• Frequency & Testing: Conduct monthly restoration tests.
• Immutability & Offline Copies: Keep immutable, offline copies with restricted, audited, and logged access.
  
  

Keep Systems and Applications Updated

• Patching & Security Monitoring: Automate asset inventory and vulnerability detection.
• Automation: Deploy patches in controlled waves, with documented rollback procedures.
• Prioritization: Fix actively exploited vulnerabilities and Internet-exposed components first.
  
  

Control and Segment Access to Information Systems

• Least Privilege Principle: Limit each identity to what is strictly necessary, with temporary, auditable, and automatically revoked access.
• Zero Trust: Never trust by default. Verify continuously and contextualize access decisions.
• Segmentation & Microsegmentation: Isolate backups, separate security domains, and limit lateral movement.
  
  

Secure Remote Access and Remote Work

• Application Containerization: Isolate sensitive sessions to prevent malware from pivoting.
• Browser Isolation: Reduce exposure to malicious links and compromised downloads.
• Secure, VPN-Free Access: Use remote access solutions with identity checks, fine-grained logging, and least privilege—ideal to counter scenarios like the SonicWall case.
  
  

What to Do in Case of an Attack?

Isolate Systems

Disconnect affected segments, disable compromised accounts, and block lateral movement.

Do Not Pay the Ransom

Paying offers no guarantee of recovery and funds criminal activity. Preserve evidence, report to the competent authorities, and notify the CNIL within required timeframes if personal data is involved.

Restore from Backup

Reinstall from trusted sources, run a full scan, reset credentials and secrets, and validate integrity before going back online.

Improve Security

Perform root cause analysis, enhance EDR rules, strengthen access controls, accelerate updates, and run disaster recovery drills.

Integrating Reemo into Your Cybersecurity Strategy

Reemo is more than just a remote desktop solution—it is a cybersecurity platform designed to secure access to critical resources and reduce your operational attack surface, with zero compromise on performance.

• Browser isolation and application containerization to prevent endpoint compromise and malware spread.
• Least privilege by design with temporary, targeted, and traceable access to minimize the impact of account takeover.
• VPN-free application access to avoid full network tunnels and limit blast radius in case of incidents—ideal against SonicWall-type scenarios.
• Internal mesh and logical segmentation to contain organization-wide attacks and protect critical data and backups.

In Summary

Ransomware protection no longer relies on a single measure.
It requires a solid foundation of regular backups, controlled updates, strict access control, and effective isolation of risky activities.
With Reemo, you combine these pillars through a platform that centralizes and secures all your remote access needs.
Want to assess your posture or modernize your remote access (VPN-free, with built-in logging and least privilege)? Let’s talk.