April 11, 2026, 8:28 a.m.

5 Critical Security Measures to Prevent Ransomware Threats When Backing Up

In today's digital world, ransomware attacks are among the most devastating cybersecurity threats organizations face. Attackers are now not only encrypting systems but also targeting backup systems to leave organizations completely helpless. Therefore, creating an effective backup strategy is one of the most important steps in providing protection against ransomware attacks. However, simply having backups is not enough; the backup processes themselves must also be protected against cyber threats.

As Nordis Global, we provide comprehensive cybersecurity consulting to help organizations ensure their data security. In this article, we will examine in detail five critical measures you need to take to protect your backup processes from ransomware threats.

Why Ransomware Attacks Target Backup Systems

Backup systems under ransomware attack

Ransomware attackers significantly increase the likelihood of ransom payment by targeting organizations' backup systems. A functioning backup system allows organizations to restore their data after an attack and continue their operations without paying ransom. For this reason, backup infrastructures are among the attackers' priority targets.

In large-scale ransomware attacks in recent years, attackers have been observed staying hidden in systems for months, first disabling backup mechanisms or encrypting backups. This tactic maximizes the likelihood of ransom payment by leaving organizations helpless.

1. Apply and Expand the 3-2-1 Backup Rule

The classic 3-2-1 backup rule recommends keeping three copies of your data, on two different media, with one off-site. However, in the face of ransomware threats, this rule needs an addition: the 3-2-1-1-0 rule.

Components of the Extended Backup Rule

• 3 copies: Keep three total copies of your data (original + 2 backups)
• 2 different media: Store backups on different storage technologies (disk, tape, cloud, etc.)
• 1 off-site location: Ensure at least one backup is in a physically different location
• 1 offline copy: Ensure one backup is completely offline (air-gapped) and not connected to the network
• 0 errors: Regularly test backup processes and ensure you can restore without errors

The offline backup copy is your last layer of security that attackers cannot access during a ransomware attack. This copy can be in the form of external drives requiring manual connection, tape systems, or physically isolated cloud storage solutions.

2. Use Immutable Backup Technology

Immutable backups are backup copies that cannot be modified, deleted, or encrypted for a certain period after creation. This technology is one of the most effective defense mechanisms against ransomware attacks.

Advantages of Immutable Backups

• Ransomware cannot encrypt or delete backup files
• Provides protection against insider threats and accidental deletions
• Guarantees data integrity for compliance requirements
• Provides support for compliance with legal and regulatory standards

Modern backup solutions offer immutable backups with object lock features. In cloud-based storage services, you can also activate this feature to ensure that your backups cannot be modified in any way for a specified period (for example, 30, 60, or 90 days).

3. Strengthen Access Controls to Backup Systems

Multi-factor authentication screen for backup systems

Your backup infrastructure is at least as critical as your production systems and requires equally strong access controls. Ransomware attacks are often carried out using stolen credentials or privilege escalation techniques.

Access Control Measures to Implement

• Multi-factor authentication (MFA): MFA should be mandatory for access to backup systems
• Principle of least privilege: Users should be given only the minimum level of privilege they need
• Privileged account management: Administrator accounts for backup systems should be protected with privileged access management (PAM) solutions
• Role-based access control (RBAC): Roles should be defined in accordance with the principle of separation of duties
• Regular access audits: Who has access to backup systems should be periodically reviewed

Additionally, in cases where remote access to backup management consoles is possible, it is important that these accesses occur through VPN or zero trust network access (ZTNA) solutions. You should never leave direct internet access to your backup systems open.

4. Continuously Monitor Backup Processes and Protect Logs

Ransomware attacks usually don't happen overnight. Attackers can remain silently in systems for weeks or even months and try to sabotage backup mechanisms before launching the attack. Therefore, continuous monitoring of your backup systems and detection of suspicious activities is critically important.

Important Indicators to Monitor

• Backup jobs failing or stopping unexpectedly
• Unauthorized changes in backup configurations
• Backup deletion operations performed at unusual hours
• Abnormal login attempts to backup accounts
• Unexpected deletion or modification of backup files
• Sudden and unexplained changes in backup storage space

Collecting backup logs in a separate and secure SIEM (Security Information and Event Management) system prevents these logs from being deleted or modified by attackers. Storing logs in an immutable manner also provides valuable evidence during forensic analysis processes.

5. Perform Regular Backup Restore Tests

No backup strategy can be considered complete without regular testing. A