A NAS manufacturer based in Taiwan called Synology recently issued a warning to its customers relating to the StealthWorker botnet. This botnet has been targeting a wide range of NAS (Network Attached Storage) devices using simple brute force tactics. Anytime the botnet succeeds in breaching the security of a NAS it will deploy a ransomware payload to encrypt any files on that device.

The botnet also stores working credentials so that its controllers can use them later to try and breach other devices on the same network. This is on the thinking that many people reuse passwords. It is a simple and effective strategy that could have devastating consequences for anyone with weak admin credentials and recycled passwords in use across multiple devices.

Synology alerted its customers to the threat itself. They are also urging all of their customers to immediately change any weak passwords and to update passwords that are in use on multiple devices. That is whether they’re on the same or a different network. This is all to be done in order to mitigate risk.

If possible the company is also urging the use of two-factor authentication to make it more difficult for the Botnet to gain traction when it makes an attack.

This Botnet and this particular line of attacks seem to favor Synology NAS devices. So if you use them at your company you should review your passwords to make sure they’re sufficiently robust right away. Also, you should enable other any other network security protections you can.

The hackers could easily shift gears and target NAS devices made by some other vendor or even target other types of devices entirely. So now would be a good time to do a general password security review just to make sure you’re not caught off guard.