I run macOS only and as far as I can tell Nymaim is Windows only. Still, I ran an malware scan on my Macbooks and nothing popped up, so I'm pretty sure nothing infected my devices.
Still, I wonder if I ended up hitting the sinkhole, Virgin was somehow notified and this triggered their email? Or maybe it's just a complete coincidence.
Edit: Sure looks like Virgin works with Shadowserver: https://www.ukfast.co.uk/it-security-news/virgin-media-to-in...