def list_elb_attached_secgroups(elb) -> list:
    """
    List security groups attached to Elastic Load Balancers
    """
    elb_attached_groups = []
    boto_load_balancers = elb.describe_load_balancers()
    for elb_obj in boto_load_balancers['LoadBalancerDescriptions']:
        for security_group in elb_obj['SecurityGroups']:
            elb_attached_groups.append(
                security_group
            )
    return elb_attached_groups