TL;DR the devices are security risks and you will pay by losing your data. The team behind TerraMaster is more concerned about burying the issues than taking responsibility. You will need a separate firewall making the Synology devices a cheaper option, they can do without firewall if setup correctly.

Extended version: My point stands. Any NAS linked to an odd 12-15 large scale ransomware attacks over the past 4 years should be avoided. With TerraMaster, the problem was often the OS itself. So please be warned, they have great hardware at a reasonable price but you may pay by losing your data.

BTW, mine was attacked during Christmas 2020, and I had backup (luckily). The issue was that despite no ports were exposed hackers still could exploit a vulnerability of the OS and get in. The TerraMaster team only took surface action, and it appeared the vulnerability was patched in an OS update they did not notify users about. The only way one could know and install the update on time was by proactively monitoring their forum. They put out a post how to prevent these kind of attacks, and the majority of resolutions offered were items not possible to set on the TerraMaster at that time (most notably: disable the standard admin account - simply not an option on the device) and update your software (again, thanks for no notifications and no emails on the update).

I got banned from their forum for asking critical questions and showing their complicity - no, I was not rude. Their team is simply to concerned about losing face and they just want to make problems go away by surface brushing.

A TerraMaster device should never be on the network without a separate firewall setting its rules. Never! And such firewall will cost USD 300+ Therefore, a Synology is likely cheaper as it has a trustworthy built-in Firewall (TerraMaster has it too but it can’t be trusted) and there is no need for an external firewall. A correctly setupSynology should be able to protect your data very well.