var contentInfo = new ContentInfo(File.ReadAllBytes(filePath));
			var signedCms = new SignedCms(contentInfo, true);

			signedCms.Decode(File.ReadAllBytes(filePath + ".ts.sig"));
			signedCms.CheckSignature(true);

			foreach (var signerInfo in signedCms.SignerInfos)
			{
				foreach (var unsignedAttribute in signerInfo.UnsignedAttributes)
				{
					if (unsignedAttribute.Oid.Value == "1.2.840.113549.1.9.16.2.25") //escTimeStamp
					{
          	Console.WriteLine("Contains TimeStamp");
          }
        }
     }