Webhard is Web Hard Drives - SK torrenting scene is very different from the west, to simplify from how I understand it (English info seems scarce) basically everyone uses seedboxes or "web hard drives" in SK to download stuff.
While I can't seem to find out anything about what "The Grid system" is, if the whole thing is an online portal or software.
If ISP routers are anything like the west that means they control the DNS servers and the ones on router cannot be changed, and likely it blocks 1.1.1.1 and 8.8.8.8 and so on, as Virgin Media does (along with blocking secure DNS) in the UK for example, which definitely opens up a massive attack vector for an ISP to spin up its own website with a verified cert and malware and have the DNS resolve to that when users try to access it to either download the software needed to access this Grid System or if it's a web portal - the portal itself.
I don't think this included any attacks on the BitTorrent protocol at all, because as others said, it's pretty secure, but another possibility is simply malicious torrents being distributed, which rights holders definitely done before (read decoying part in https://arstechnica.com/tech-policy/2007/03/mediadefender/)