I think that depends on whether you want to trust already-executing programs or not. If you trust them, then sure, it's pretty straightforward: you just tell th

I think that depends on whether you want to trust already-executing programs or not. If you trust them, then sure, it's pretty straightforward: you just tell the AV what to scan vs. not. If you don't, then it's not: you have to either offload the copying to kernel-mode, or delegate it to a secured user-mode process, because otherwise a malicious program could just modify the buffer you're copying from. The former makes sense from a performance standpoint but the latter also makes sense from a security standpoint.