You'd need the editbugs privilege. Then you'd be able to [tag the comment as spam](https://wiki.mozilla.org/BMO/comment_tagging) So bugzilla already has this but it's somewhat restricted so as not to be abused.
Bug 1881290 Comment 2 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
You'd need the editbugs privilege. Then you'd be able to [tag the comment as spam](https://wiki.mozilla.org/BMO/comment_tagging) So bugzilla already has this but it's somewhat restricted so as not to be abused. I've marked the offending comment as spam and also marked to attachment as obsolete so it won't be displayed by default any more.