I created a subdomain forum.example.com
I opened the forum and went on holiday for a month, and when I came back to my shock I found 100 (1000's) of spam links posted to my subdomain's forum.
My site has quite a good reputation and a solid link profile. I get about 50k visitors per month of which 30% is from organic.
What worries me now is when I do a search in google like site:example.com
many of those subdomain forum spam posts show up!
I have since deleted the subdomain and made a 410 for forum.example.com
Am I likely to face a penalty for this slip up...? Any idea if this will effect my main domain's ranking?