Does anyone here know why (apparently) all Wikimedia content wikis just got a new adminstrator called "Abuse filter" (in the local language)? This happened on December 17th at around 3–6am UTC. Shouldn't this have happened long ago when the AbuseFilter extension was first installed/enabled on Wikimedia wikis?
Topic on Extension talk:AbuseFilter
It has to do with this: phab:T209565
Special:CentralAuth/Abuse_filter shows only a handful of wikis (presumably the ones that have AbuseFilter-imposed blocks enabled), and the accounts were attached between July 2014 and April 2015. You say there are other accounts with localized names?
Just look at 'Special:ListAdmins' on "any" Wikimedia wiki (examples: w:csb: s:eo: voy:uk:). You'll probably see a redlinked username that corresponds to "Abuse filter" in the local language of that wiki, that was created on 17 December 2018. The list at 'Special:CentralAuth/Abuse_filter' presumably (per Daimona Eaytoy below) contains the only WM wikis that didn't get a new admin created on that date.
Thanks to everyone for the info.
The task above has all the info, which I'll sum up below. Yes, the AbuseFilter extension owns a system user with localized name (msg is "abusefilter-blocker"), used mainly to block users (and a couple of minor other things). In the linked patch we launched a script to clean up some filters across wikis which have wrong syntax, and we decided to use such user to perform the task. While the script hasn't made any changes for now, the account has been automatically created where it didn't exist. On wikis with block enabled, the user exists since the day block was enabled, which could be back to 2008 when the extension was created. In short, don't worry about it; we'll write a couple of lines in tech news before the final run.
See also: phab:T212268.