A storage device that holds years of business documents, customer records, and important company files can become a serious security risk when its software is left outdated. Recent ransomware attacks targeting Synology NAS devices demonstrate how cybercriminals can exploit known vulnerabilities to lock valuable business data and demand payment for its recovery.
KIS Technologies Inc. offers cybersecurity and data protection services to help businesses prevent these threats, secure their IT infrastructure, and recover critical information when incidents occur. We have solutions to help organizations strengthen their security and avoid costly disruptions caused by ransomware.
Synology NAS Devices Are Being Targeted by Ransomware
Synology recently warned customers about ransomware attacks targeting Network Attached Storage (NAS) devices running outdated versions of its DiskStation Manager (DSM) software. According to the company, attackers are exploiting a vulnerability that was already patched in December 2024.
The attacks are designed to encrypt files stored on compromised devices and demand ransom payments from affected users. This is particularly concerning for businesses that depend on NAS devices to store shared documents, financial records, customer information, and backup copies of important files.
The ransomware involved in reported incidents has been identified as C3RB3R. Once a device is compromised, the malware scans its stored files and encrypts selected data. Affected files receive a .L0CK3D extension, while a ransom note named read-me3.txt appears in encrypted directories.
Synology has urged customers to update their DSM software immediately and enable automatic updates. Businesses can read the company’s official security announcement for additional information.
Why Outdated NAS Devices Are a Serious Security Risk
A NAS device provides centralized storage that allows multiple employees and computers to access shared information through a network. It is a convenient solution for businesses that need accessible storage without maintaining separate copies of every file on individual computers.
However, convenience also introduces security concerns when these devices are not properly maintained.
Known Vulnerabilities Can Give Attackers Access
One of the biggest problems with outdated software is that attackers can exploit vulnerabilities that manufacturers have already identified and fixed.
In Synology’s November 2024 security advisory, CVE 2024 10441 was rated critical, with a CVSS score of 9.8. The vulnerability could allow remote attackers to execute arbitrary code on affected systems.
More recently, Synology addressed additional critical DSM vulnerabilities in September 2026, including CVE 2026 13684 and CVE 2026 13639. These issues could allow remote attackers to read or write arbitrary files under certain conditions.
Businesses should review the latest Synology DSM security advisory and verify that their devices are running the latest supported software.
A Compromised NAS Can Affect an Entire Business
The consequences extend beyond losing access to a few documents.
If employees depend on a compromised NAS for daily operations, ransomware can prevent them from accessing shared files, accounting records, project documents, and other essential resources. Business operations may come to a standstill while IT teams investigate the incident and attempt to restore the affected information.
The situation becomes even worse when the NAS also stores backup copies of company data. If attackers can access and encrypt those backups, restoring operations becomes significantly more difficult.
5 Ways Businesses Can Protect Their NAS Devices From Ransomware
Protecting business storage requires more than installing antivirus software. Organizations need multiple layers of security to reduce the chances of an attack and minimize its impact.
1. Keep DSM and Device Software Updated
Install the latest available DSM updates and security patches as soon as possible. Enable automatic updates where appropriate, and regularly check whether additional updates are available for installed applications and packages.
Businesses should also review older NAS devices that may no longer receive security updates. Unsupported equipment can become an ongoing security concern.
2. Avoid Exposing NAS Management Interfaces to the Internet
Remote access is useful, but exposing administrative interfaces directly to the internet increases the opportunities for attackers to target a device.
Restrict management access to trusted networks and authorized users. If employees need remote access, consider using a properly configured VPN rather than making the NAS administration interface publicly accessible.
A properly configured firewall and network security solution can help control incoming connections and prevent unauthorized access to business infrastructure.
3. Use Strong Passwords and Multi Factor Authentication
Weak administrative credentials make it easier for attackers to gain access through password guessing and brute force attempts.
Businesses should use unique, complex passwords for administrative accounts, disable unused accounts, and enable multi factor authentication wherever supported.
Access should also be limited according to employee responsibilities. Not everyone needs administrative privileges or unrestricted access to company storage.
4. Maintain Separate and Reliable Backups
Having a NAS device does not automatically mean your business has adequate backup protection.
A proper backup strategy should include separate copies of important data, ideally with at least one offline or immutable backup that ransomware cannot easily modify or delete.
Regularly test backup restoration to confirm that files can actually be recovered when needed.
The CISA Ransomware Guide also recommends maintaining offline, encrypted backups and regularly testing recovery procedures.
Businesses can strengthen their recovery plans through professional data recovery and backup services that provide automated backups, monitoring, and recovery options.
5. Monitor Systems for Suspicious Activity
Unexpected login attempts, unusual file modifications, and unexplained changes to backup configurations can indicate a potential security incident.
Regular monitoring helps identify suspicious activity before it develops into a more serious problem. Businesses should also ensure that security alerts are reviewed and investigated rather than simply ignored.
Professional cybersecurity services can provide ongoing monitoring, threat detection, and security assessments to help identify weaknesses across an organization’s IT environment.
What Should You Do If Your NAS Device Is Already Compromised?
If you discover files with the .L0CK3D extension or find ransom notes on your Synology device, treat the situation as a potential security breach.
Immediately isolate the affected device from the network where practical to prevent further damage. Avoid deleting suspicious files or attempting random recovery tools that could make the situation worse.
Contact qualified IT security professionals to investigate the incident, determine the extent of the compromise, and establish a safe recovery process. Affected credentials should also be changed from a clean device.
Most importantly, do not assume that paying the ransom guarantees that your files will be recovered. Restoration from clean, unaffected backups is generally a safer recovery approach.
Protect Your Business Before Ransomware Strikes
The recent attacks against Synology NAS devices are a reminder that even established storage solutions require regular maintenance and proper security management. A single outdated device can put important company information and daily operations at risk.
KIS Technologies provides businesses with cybersecurity, network protection, backup planning, and managed IT services designed to reduce these risks. Whether your organization relies on NAS storage, local servers, or cloud infrastructure, having the right security measures in place can make a significant difference when threats emerge.
Do not wait until your business files are encrypted to review your security. Contact KIS Technologies to discuss how your organization can improve its cybersecurity and data recovery strategy.