Ransomware Alert - Ransomware Attacks Targeting Synology NAS Devices
Published Sources: HKCERT
What is affected, what to do
Solutions Preventive and Remediation Measures HKCERT recommends that users and system administrators: Update DSM immediately: Upgrade to the latest applicable DSM version that is supported by both the device and the vendor. Users running end-of-life versions should plan an upgrade.
The available sources name no fixed version. Check the vendor guidance in the references below.
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Metrics
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Priority
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CVSS v3
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EPSS score
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- Severity
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Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 30.00 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
Solutions Preventive and Remediation Measures HKCERT recommends that users and system administrators: Update DSM immediately: Upgrade to the latest applicable DSM version that is supported by both the device and the vendor. Users running end-of-life versions should plan an upgrade. If the device cannot run a supported version, consider replacing it. For affected versions and patch details, please refer to Synology urges users to apply security updates, extends PHP2Shell fixes to older DSM releases Update PHP and affected packages: Install the PHP security updates through Package Center. Updates are available for DSM 7.4, 7.3, 7.2, 7.1, 7.0 and 6.2. Dependent packages restart automatically after the PHP update. MailStation requires a separate manual update through Package Center. These fixes do not mean that end-of-life DSM versions have returned to full support. For detailed instructions, please refer to Synology Extends PHP2Shell Security Updates to End-of-Life DSM Versions Address older systems: For systems running DSM versions earlier than 6.2, temporarily disable the affected packages as recommended by the vendor, then upgrade to a supported DSM version. Reduce network exposure: Avoid exposing NAS management interfaces directly to the internet. Disable unnecessary services and port forwarding, and restrict remote access. Protect important data: Maintain offline or immutable backups and regularly test restoration procedures. Actions for Suspected Infection If files are unexpectedly encrypted or ransom notes appear, HKCERT recommends: Isolate the affected device immediately: Disconnect the NAS from the network and suspend connected synchronisation and backup jobs to help prevent other data or backups from being affected. Preserve evidence: Retain ransom notes, encrypted file samples, system logs and access logs, and record when the suspicious activity was discovered. Avoid resetting, formatting or unnecessarily restarting the device. Seek incident response assistance: Contact IT support or an incident response service provider to investigate the entry point and determine the scope of the compromise. Restore services only after remediation: Remove malware and unauthorised access, install security updates, and reset potentially compromised credentials from a clean device. Restore data from verified clean backups only after the environment has been secured. Do not rely on ransom payment for recovery: Paying the ransom does not guarantee data recovery. Installing security updates will not decrypt files already encrypted by ransomware. Businesses or members of the public who wish to report to HKCERT on information security related incidents such as malware, phishing, denial of service attacks, etc. can do so by completing the online form at: https://www.hkcert.org/incident-reporting , or calling the 24-hour hotline at +852 8105 6060. For further enquiries, please contact HKCERT at hkcert@hkcert.org . Reference： Synology urges users to apply security updates, extends PHP2Shell fixes to older DSM releases Synology Extends PHP2Shell Security Updates to End-of-Life DSM Versions
Source: HKCERT (CC BY 3.0 HK)