How is the "Exterminator" badge awarded?

Exterminator | Khan Academy Wiki | Fandom

The staff will decide if you indeed made a contribution in order for you to earn the badge. 

Hi Andrew,

If you've submitted an effective bug report for a technical issue, I believe you should be eligible to receive the Exterminator badge. 

This badge has to be awarded manually, so you'll need to reply to the bug report or submit a new ticket requesting that the badge be awarded to you.

Thanks for your help!