How to foil SynoLocker and minimize the damage

We wrote on Monday warning about Synology NAS users being targeted with SynoLocker, a customized version of the Cryptolocker ransomware, which encrypts the files contained on the devices and asks 0.6 BitCoin ($350) for the decryption key.

It is still not known how the malware manages to compromise the devices, but Synology says that so far, it looks like the problem is localized to non-updated versions of DiskStation Manager (DSM) 4.3. They are still researching the issue to see if it effects DSM 5.0 as well.

“In the interim, we are asking people to take the following precautions: close all open ports for external access as soon as possible, and/or unplug your Disk/RackStation from your router, update DSM to the latest version, and backup your data as soon as possible,” the company advised, and promised to provide further information as soon as it’s available.

In case your NAS has been infected, Synology urges you not to trust any email from unauthorized/non-genuine Synology email. “Synology email always has the ‘synology.com’ address suffix,” they noted.

“Do a hard shutdown of your Disk/RackStation to prevent any further issues. This entails a long-press of your unit’s power button, until a long beep has been heard. The unit will shut itself down safely from that point,” they advise. “Contact Synology Support as soon as possible.”

UPDATE:

“Based on our current observations, this issue only affects Synology NAS servers running some older versions of DSM (DSM 4.3-3810 or earlier), by exploiting a security vulnerability that was fixed and patched in December, 2013. Furthermore, to prevent spread of the issue we have only enabled QuickConnect to secure versions of DSM. At present, we have not observed this vulnerability in DSM 5.0,” Synology announced.

“For Synology NAS servers running DSM 4.3-3810 or earlier, and if users encounter any of the below symptoms, we recommend they shutdown their system and contact our technical support team,” they advised.

Users who were not affected by the SynoLocker ransomware are encouraged to download and installing DSM 5.0, or any of the following versions:

• For DSM 4.3, please install DSM 4.3-3827 or later
• For DSM 4.1 or DSM 4.2, please install DSM 4.2-3243 or later
• For DSM 4.0, please install DSM 4.0-2259 or later.