During the 'Gun Mettle' update, the attributes of a lot of weapons were changed. One of the background changes was to assign 'prefabs' to several of the stock strange weapons, but in an oversight a few of those weapons were made to default to 'Normal' quality. The glitch lasted for ~23 hours and during that time frame any of the affected weapons unboxed or awarded in MvM were Normal Quality.

There is only 1 instance of this item in 'Strange Normal' quality, however the owner got his Steam account banned.