From Paragon Wiki
You have defeated 75 witches, sorcerous crones who use dark magicks.
- This badge is awarded for defeating Witches during Halloween Events. It is awarded only during these events.
- Presumably named for the 15th century German witch-hunt manual "Malleus Maleficarum", Latin for "Hammer of Witches" or "Hammer Against Witchcraft" (more or less - the "Malleus" part means "hammer").