I have one of these but am unable to access the dowloads page for firmware updates. It's far from clear that the recent DNS hack issue applies to this version of the router.
I have registered my router via the router software, but that user name/password seems unrelated to that on the www.draytek.co.uk web site. I tried to register there but didn't receive the activation email so can't log on. For some reason although the latest version 3 firmware is publicly available, the version 1... firmware is not.

Help.

No idea if the DNS issue applies to V1 but have you tried this link? http://www.draytek.com.tw/ftp/Vigor2760/Firmware/

I don't think the V1 firmware is affected by this specific issue but that firmware version was superceded many years ago so you presumably have avoided all updates which will have had misc. other security improvements so you really should upgrade to 3.x.x