Get Off Those Maliciously Loaded Scripts!
Download this free Anti-Malware Plugin for WordPress.

First: Never trust an AI to give accurate information. This is not in any way evidence of a persistent malware infection. This is simply a feature of my Firewall which protects against URLs with User Enumeration, like the “posts by author” link you are trying to get working.

If you delete my plugin then it will no longer protect against this potential threat, but if just disable that one feature on the Firewall Options page in your wp-admin then you can user links with author IDs and also still have all the other protections that my plugin has to offer.

Please let me know if you need more help or have any further questions.