Kali Linux recently announced that packet injection is now supported in release 2017.1 for the Realtek RTL8812AU 802.11ac chipset, which is found in Alfa USB Wi-Fi models AWUS036ACH, AWUS036AC, and AWUS036EAC. According to their web site:
"A while back, we received a feature request asking for the inclusion of drivers for RTL8812AU wireless chipsets. These drivers are not part of the standard Linux kernel, and have been modified to allow for injection. Why is this a big deal? This chipset supports 802.11 AC, making this one of the first drivers to bring injection-related wireless attacks to this standard, and with companies such as ALFA making the AWUS036ACH wireless cards, we expect this card to be an arsenal favourite."
This announcement is extremely awesome in that it makes these products the first 802.11ac USB products capable of injecting in Kali Linux. Pick up yours today for a low price. Need Linux technical support? Visit our support page for details on what type of help our company can provide for Linux users.
Military and First Responder 
i’ve got one (ALFA AWUS036ACH)
i’m using Kali Linux 2017.1 on VM
but i’ve failed to update the drivers. (root@kachi:~# apt update
Reading package lists… Done
Building dependency tree
Reading state information… Done
All packages are up to date.
root@kachi:~# apt install realtek-rtl88xxau-dkms
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package realtek-rtl88xxau-dkms
root@kachi:~# )
what can i do, please help