factory.Credentials.UserName.UserName = "bob";
factory.Credentials.UserName.Password = "abc!123";

// create token request
var rst = new RequestSecurityToken
{
    RequestType = RequestTypes.Issue,
    KeyType = KeyTypes.Symmetric,
    AppliesTo = new EndpointReference(_serviceAddress.AbsoluteUri)
};

private GenericXmlSecurityToken NewGetAdfsSamlTokenWinAuth()
    {
        try
        {
            WS2007HttpBinding binding = new WS2007HttpBinding(SecurityMode.Transport);
            binding.Security.Message.EstablishSecurityContext = false;
            binding.Security.Message.ClientCredentialType = MessageCredentialType.Windows;
            WSTrustChannelFactory factory = new WSTrustChannelFactory((binding), new EndpointAddress(this.adfsIntegratedAuthUrl));
            factory.TrustVersion = TrustVersion.WSTrustFeb2005;
            factory.Credentials.SupportInteractive = false;
            var rst = new RequestSecurityToken
            {
                RequestType = RequestTypes.Issue,
                AppliesTo = new EndpointReference("urn:federation:MicrosoftOnline"),
                KeyType = KeyTypes.Bearer
            };
            IWSTrustChannelContract channel = factory.CreateChannel();
            return channel.Issue(rst) as GenericXmlSecurityToken;
        }
        catch (Exception ex)
        {
            // Do something with the exception
        }
        return null;
    }