Ensure AES 256/256 Cipher Suite is enabled (Scored)

Best practice for systems running IIS, part of Hardening IIS:

Manual verification

Ensure the following key do not exist or is set to 0xFFFFFFFF:

REG QUERY "HKLM\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AES 256/256" /v "Enabled"

Implement Recommended Configuration

Set Registry key

REG ADD "HKLM\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AES 256/256" /f /v "Enabled"  /t REG_DWORD /d 0xFFFFFFFF

Use IIS Crypto

IIS Crypto is a free tool that gives administrators the ability to enable or disable protocols, ciphers, hashes and key exchange algorithms on Windows Server 2008, 2012 and 2016. It also lets you reorder SSL/TLS cipher suites offered by IIS, implement best practices with a single click, create custom templates and test your website.

Nessus audit file check

<custom_item>
 type : REGISTRY_SETTING
 description: "IIS800043:Disable Weak Cipher Suites - 'HKLM\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AEX 256/256\Enabled = ffffffff':IIS8"
 value_type : POLICY_DWORD
 reg_key : "HKLM\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\AEX 256/256"
 reg_item : "Enabled"
 value_data : 4294967295
 reg_option : CAN_NOT_BE_NULL
</custom_item>