If the driver file is signed, then it should contain a valid X509
certificate, so one way to check this is by using using the
System.Security.Cryptography.X509Certificates namespace.
Here a small snip to get you started..

using System;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
...

  X509Certificate certp =
X509Certificate2.CreateFromSignedFile(@"C:\Windows\System32\drivers\tcpip.sys");
  X509Certificate2 x509 = new X509Certificate2(certp.Handle);
  // if valid, dump some properties to the console
  Console.WriteLine("{0}Subject: {1}{0}",
Environment.NewLine,x509.Subject);
  Console.WriteLine("{0}Issuer: {1}{0}", Environment.NewLine,x509.Issuer);
  Console.WriteLine("{0}Version: {1}{0}",
Environment.NewLine,x509.Version);
  Console.WriteLine("{0}Valid Date: {1}{0}",
Environment.NewLine,x509.NotBefore);
  Console.WriteLine("{0}Expiry Date: {1}{0}",
Environment.NewLine,x509.NotAfter);
  Console.WriteLine("{0}Thumbprint: {1}{0}",
Environment.NewLine,x509.Thumbprint);
  Console.WriteLine("{0}Serial Number: {1}{0}",
Environment.NewLine,x509.SerialNumber);
  Console.WriteLine("{0}Friendly Name: {1}{0}",
       Environment.NewLine,x509.PublicKey.Oid.FriendlyName);
  Console.WriteLine("{0}Public Key Format: {1}{0}",
        Environment.NewLine,x509.PublicKey.EncodedKeyValue.Format(true));
  Console.WriteLine("{0}Raw Data Length: {1}{0}",
Environment.NewLine,x509.RawData.Length);
  Console.WriteLine("{0}Certificate to string: {1}{0}",
Environment.NewLine,x509.ToString(true));

Willy.