Some players use multiple PCs and a physical KVM switch. This is the "cleanest" way to avoid software-based bans, though it is expensive.
Searching for cracked versions of niche software like Pwnboxer is a high-risk activity for several reasons: CRACK Pwnboxer V02.02.0215.01l
If you are looking for multiboxing capabilities, consider these legitimate paths: Some players use multiple PCs and a physical KVM switch