Agreed with @pau4ner - you should walk through all the spam signals and fix what you can. It sucks that some of the spam signals Moz has chosen can be bad (in other ways like adverse to pagespeed) to implement, like having a custom font - if not needed this slows your site and reduces your pagespeed - so to have to add a custom font just to please Moz's spam score is unfortunate - but if you want to improve your score - implement the 27 factors listed at the link @pau4ner gave. Also note they only update it quarterly, so even after fixing your site you might be in for a good wait to see an update.
What is further annoying is that even if you are in the low spam range at say 24% (e.g. my site atm: https://discoverquotes.com) still.. most webmasters see 24% and think that is a lot - so they won't link to my site. Moz's Spam Score is hurting me unfairly, IMHO, because my site is not spammy, and because many of the 27 items - things they feel you should have like custom font and linked in and ad scripts and google analytics scripts - all those things adversely affect page speed. So you can have a fast site, or comply with Moz's spam score requirements, but doing both is a challenge.
