In this excerpt from Abhinavagupta’s Tantraloka, Swami Lakshmanjoo explains what Malas (Impurities) really are in Kashmir Shaivism.

Mala is absence of knowledge. Mala is not something substantial. ~Swami Lakshmanjoo

“This mala is very subtle. . . . Mala is neither formless nor with form.
It is just ignorance . . . It doesn’t allow knowledge to function, knowledge is stopped.  Mala is absence of knowledge. Mala is not something substantial.

So this absence of knowledge takes place only by ignorance, and...