Subdomain Spam URLs Causing High Clicks and Impressions?

- My subdomain was hacked. As a result, spam URLs appeared in my Google Search Console, but not on my main domain. They started being indexed on November 29, 2025.
- My impressions increased drastically.
- I removed the URLs and changed them to 404 status.
- My impressions and clicks remained steady from December 2, 2025 to January 21, 2026.
- Now, after Google Search Console has completely removed the URLs from the report, my impressions and clicks have dropped significantly.

My question is:

1. Does a “Not indexed” URL affect website impressions and clicks?
2. Does sub-domain affect main domain?

1. "Not indexed” does not directly affect your rankings, but it does affect your impressions report if those urls were previously generating impressions (which is exactly what happened with the hacked spam pages). Your drop is simply the loss of fake / irrelevant impressions, not a hidden penalty

2. subdomain is treated as a separate site, but security abuse on a subdomain can indirectly hurt trust if it becomes a pattern (same ownership, same hosting, repeated abuse)

You should probably have used a 410 response for those urls rather than 404. 410 indicates that the pages are gone 'forever' (hopefully), whereas 404s indicate that something has gone wrong or some big churn/changes have happened. They're both 'errors', but 404 looks much worse when looking at domain health.

Yes. Once spam URLs are removed or “Not indexed,” they stop generating impressions and clicks, which explains the drop.

Subdomains are mostly separate, so spam there doesn’t usually hurt the main domain. Focus on securing the subdomain and monitoring your real pages.

Once those spam urls got cleared google recalculated visibility so the fake impressions vanished that’s why clicks droppednot cause google punished you.

first, not indexed urls don’t directly give you impressions. if a page isn’t indexed, it can’t rank, so it can’t generate search impressions. what probably happened is those spam urls were indexed for random junk queries, inflating your impressions temporarily. once they dropped out, your numbers normalized. feels like a drop, but it was artificial lift.

second, yes… subdomains can affect the main domain indirectly. technically google treats them as separate properties, but trust, crawl budget, and overall domain reputation are connected signals. if the subdomain was hacked and pushing spam, that can dilute trust or trigger quality signals across the root.

the key now is to check core rankings. did your actual money keywords drop, or just impressions? if real keywords dropped, strengthen your clean pages. tighten internal linking, improve content depth, and build diversified backlinks to reinforce authority again. sometimes after cleanup, google recalculates trust and you need to push quality signals back in.

Yes, subdomain will effect the root domain.