Pure
Katasha is a modern American elaboration of the name Natasha, which itself is a Russian diminutive of Natalia. It combines the 'Kat' prefix, often associated with Katherine, with the rhythmic ending of Natasha, ultimately rooted in the Latin phrase meaning 'birthday' or 'Christmas Day'.
Less common today
Katasha isn't in the latest US Top 1000. It last peaked at #5,702 in 1990.
US births per 5-year period, 1990βpresent (SSA data).