Practical guide

How to prevent ransomware in an SMB

Practical ransomware prevention guide for SMBs: backups, MFA, EDR, segmentation, training, and incident response.

Author

Équipe éditoriale Cybernow

Rédaction et coordination des contenus cybersécurité

Équipe responsable de la préparation, de la mise à jour et de la coordination des contenus pratiques de Cybernow. Les sujets techniques et réglementaires doivent être attribués à un spécialiste identifié avant publication finale.

Areas of expertise

  • Cybersécurité pour PME
  • Services managés
  • Gouvernance et risques
Published 2026-04-24Updated 2026-04-24

Problem

Ransomware can stop operations, block billing, and expose customer data.

Expected outcome

A realistic layered defense for SMBs without a large IT team.

8 minutesCybernow

Block compromised access

Most attacks start with a stolen account, weak password, or exposed access.

  • Enable MFA on email, VPN, admin, and critical SaaS.
  • Disable dormant accounts.
  • Review administrator rights monthly.

Make backups restorable

A backup that is never tested is not a recovery plan.

  • Keep an offline or immutable copy.
  • Test a full restore every quarter.
  • Document expected recovery time.

Detect before mass encryption

EDR, logging, and alerts reduce the time between intrusion and containment.

  • Deploy EDR on endpoints and servers.
  • Monitor account creation and privilege escalation.
  • Prepare a network isolation playbook.

Frequently asked questions

Is MFA enough against ransomware?

No. It sharply reduces compromised access risk, but must be combined with backups, EDR, segmentation, and training.

How many backups should we keep?

Use at least a 3-2-1 strategy with one immutable or offline copy.

What should we do first after an attack?

Isolate affected systems, preserve logs, contact insurance, and activate the response plan.

Methodology and limitations

This content is a practical synthesis intended to guide an initial review. Applicable priorities, timelines, costs, and controls depend on your environment, assets, and risk level; validate them before making a decision.

Useful primary references:

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