Important Information about Ransomware SynoLocker Threat

Publish Time: 2014-08-07 00:00:00 UTC+8

Last Updated: UTC+8



It is confirmed that Synology NAS servers running older versions of DiskStation Manager are being targeted by a ransomware known as “SynoLocker,” which exploits two vulnerabilities that were fixed in November and December, 2013, respectively. At that time, Synology released security updates and notified users to update via various channels.

Common Symptoms

Affected users may encounter one of the following symptoms:

  • When attempting to log in to DSM, a screen appears informing users that their data has been encrypted and a fee is required to unlock data.
  • Abnormally high CPU usage or a running process called “synosync” (which can be checked at Main Menu > Resource Monitor).
  • DSM 4.3-3810 or earlier; DSM 4.2-3236 or earlier; DSM 4.1-2851 or earlier; DSM 4.0-2257 or earlier is installed, but the system says no updates are available at Control Panel > DSM Update.


For users who have encountered the above symptoms, please shutdown the system immediately to avoid more files from being encrypted and contact our technical support to confirm whether the system is infected. Please note Synology is unable to decrypt files that have already been encrypted.

If you happen to possess a backup copy of your files (or there are no critical files stored on your DiskStation), we recommend following the below steps to reset your DiskStation and re-install DSM. However, resetting the DiskStation removes the information required for decryption, so encrypted files cannot be decrypted afterward.

  1. Follow the steps in this tutorial to reset your DiskStation:
  2. The latest version of DSM can be downloaded from our Download Center here:
  3. Once DSM has been re-installed, log in and restore your backup data.

For other users who have not encountered the above symptoms, Synology strongly recommend downloading and installing DSM 5.0, or any version below:

  • DSM 4.3-3827 or later
  • DSM 4.2-3243 or later
  • DSM 4.0-2259 or later
  • DSM 3.x or earlier is not affected

Users can manually download the latest version from our Download Center and install it at Control Panel > DSM Update > Manual DSM Update.