leebow, I'm not sure that disavowing links that you yourself didn't build to your site is your prime concern. Junk links are common enough that they can often be disregarded.
But the attacking of your ranking that can give you real problems might be via a hijack attempt, which can do much more damage, say, than negative SEO with bad links only. Negative SEO for me doesn't make sense as a business model.
But I would watch for concerted efforts to harm the functioning of your site directly, and then add a "payload" to it. Hijacking or churn and burn hacking usually involves a network of hacked or hijacked sites which in turn funnel PageRank to target sites. In some cases, the hacked site can be both a target and a relay site.
Initially, it helps the hacker or hijacker to weaken your site enough so it becomes an easier prey. The process can involve disrupting some part of your hosting infrastructure which makes your site work, either hacking your server... or dns hijacking or spoofing Googlebot to weaken your site. If your site is weak to start with... say, not well-linked yet... that could make you vulnerable from the outset.
Malware and unpatched servers or CMS software are also big problems.
I suggest that you view your site as Googlebot to make sure that pages haven't been modified as receptors or feeders (adding spam links visible only to Googe, etc.) The number and variety of scenarios is almost too numerous to list. Definitely keep your server well patched, keep an eye on traffic, etc
I'll list below several threads that might help (and I'd use our site search here to search for more on the topic)....
Understanding hacked sites that rank in Google April, 2013 https://www.webmasterworld.com/google/4561487.htm [webmasterworld.com]
How Hacked Servers Can Hurt Your Traffic Dec, 2008 https://www.webmasterworld.com/google/3802274.htm [webmasterworld.com]
This thread contains references and links to many other threads and discussions we've had here, and I recommend you follow those...
My site's being de-indexed and replaced by others Feb, 2016 https://www.webmasterworld.com/google/4790240.htm [webmasterworld.com]
This is just a small sample of what's out there. I hope that hijacking is not your issue.
Incidentally, it's "scraper", not "scrapper."