How common are unused accounts on active directory and should they be addressed?

I'm a new security analyst with very minimal job requirements other than waiting for pagerduty to go off so I can triage security incidents.

So I'm bored most of the time and looking for stuff to do. Well I opened ADUC last night and noticed we have this account named kskdufdbelxpru under users. Created in 2020, no group memberships other than domain users, lastlogondate is null, pw is expired. whenChanged date is January 2023 though. I guess someone noticed it's …

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