command line support (partial) via PEB stomping

This update include support to passing command line parameters to unmanaged exe via PEB stomping. This technique is not working with every executable since it depends on which functions are used to pass arguments. Generally, to get a universally working technique would be required to hook GetCommandlineA GetCommandlineW __getmainargs and __wgetmainargs since PEB stomping won't cover all cases, more details here: https://blog-30cm-tw.translate.goog/2020/08/windows-c-mainargc-argv.html?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=it&_x_tr_pto=wapp However, during my testing I found that mimikatz and several go binaries are working just by doing PEB stomping. On the other hand, cmdline passing via PEB stomping alone to mingw and VS compiled binaries won't likely work.
2026-06-06 16:24:25 +00:00 · 2023-07-27 06:44:29 -07:00
parent 63ebe1c4ba
commit db1893910c
160 changed files with 70537 additions and 42 deletions
@@ -0,0 +1,70 @@
+import windows
+from windows import winproxy
+from windows.crypto import DEFAULT_ENCODING
+import windows.generated_def as gdef
+
+import ctypes
+
+__all__ = ["sign", "verify_signature"]
+
+def sign(cert, msg, detached_signature=False, algo=gdef.szOID_RSA_SHA256RSA):
+    # hash algorithm
+    alg_hash = gdef.CRYPT_ALGORITHM_IDENTIFIER()
+    alg_hash.pszObjId = algo.encode()
+
+    # Signing parameters
+    sign_para = gdef.CRYPT_SIGN_MESSAGE_PARA()
+    sign_para.cbSize = ctypes.sizeof(sign_para)
+    sign_para.dwMsgEncodingType = DEFAULT_ENCODING
+    sign_para.pSigningCert = gdef.PCERT_CONTEXT(cert)
+    sign_para.HashAlgorithm = alg_hash
+    sign_para.pvHashAuxInfo = None
+    sign_para.cMsgCert = 0
+    sign_para.rgpMsgCert = None
+    sign_para.cMsgCrl = 0
+    sign_para.rgpMsgCrl = None
+    sign_para.cAuthAttr = 0
+    sign_para.rgAuthAttr = None
+    sign_para.cUnauthAttr = 0
+    sign_para.rgUnauthAttr = None
+    sign_para.dwFlags = 0
+    sign_para.dwInnerContentType = 0
+    sign_para.HashEncryptionAlgorithm = alg_hash
+    sign_para.pvHashEncryptionAuxInfo = None
+
+    ByteBuffer = windows.utils.BUFFER(gdef.BYTE)
+
+    result_buffer = ByteBuffer(nbelt=0x2000)
+    result_size = gdef.DWORD(len(result_buffer))
+    buff = ByteBuffer(*bytearray(msg))
+    buff_pr = windows.utils.BUFFER(gdef.LPBYTE, nbelt=1)(buff)
+    buff_size = gdef.DWORD(len(msg))
+    try:
+        windows.winproxy.CryptSignMessage(sign_para, False, 1, buff_pr, buff_size, result_buffer, result_size)
+    except WindowsError as e:
+        if not e.winerror == gdef.ERROR_MORE_DATA:
+            raise
+        result_buffer = ByteBuffer(nbelt=result_size.value)
+        windows.winproxy.CryptSignMessage(sign_para, False, 1, buff_pr, buff_size, result_buffer, result_size)
+    return bytearray(result_buffer[:result_size.value])
+
+
+def verify_signature(cert, encoded_blob):
+    # Verify parameters
+    verif_param = gdef.CRYPT_KEY_VERIFY_MESSAGE_PARA()
+    verif_param.cbSize = ctypes.sizeof(gdef.CRYPT_KEY_VERIFY_MESSAGE_PARA)
+    verif_param.dwMsgEncodingType = windows.crypto.DEFAULT_ENCODING
+    verif_param.hCryptProv = None
+    # The public key used
+    pubkey = cert.pCertInfo[0].SubjectPublicKeyInfo
+    # Preparing in/out buffer/size
+    signed_buffer = windows.utils.BUFFER(gdef.BYTE).from_buffer_copy(encoded_blob)
+    decoded_buffer = windows.utils.BUFFER(gdef.BYTE).from_buffer_copy(encoded_blob)
+    decoded_size = gdef.DWORD(len(decoded_buffer))
+    winproxy.CryptVerifyMessageSignatureWithKey(verif_param,
+                                                    pubkey,
+                                                    signed_buffer,
+                                                    len(encoded_blob),
+                                                    decoded_buffer,
+                                                    decoded_size)
+    return bytearray(decoded_buffer[:decoded_size.value])