In Avast Antivirus before v17, an unprivileged user (and thus malware or a virus) can mark an arbitrary process as Trusted from the perspective of the Avast…

In Avast Antivirus before v17, an unprivileged user (and thus malware or a virus) can mark an arbitrary process as Trusted from the perspective of the Avast product. This bypasses the Self-Defense feature of the product, opening a door to subsequent attack on many of its components.