Synology PSIRT (Product Security Incident Response Team) has recently seen and received reports on an increase in brute-force attacks against Synology devices. Synology's security researchers believe... Brute-Force Attacks From a Botnet are being investigated by Synology.
From the get go I enable a very long list of IP blocking on my Synology NAS, and that list is updated. The pFsense pfblocker adds another level of malware, tracking blocking. Even so, enabled 2AF for another layer of security. Still, looking at this and learn from it.