Outdated Wordpress version is used.
Huge amount of blacklistings on that ASN/IP : https://www.virustotal.com/en/ip-address/72.29.69.252/information/ http://urlquery.net/report.php?id=1496765409224
Vulnerable libraries used : http://retire.insecurity.today/#!/scan/0cff229ff31495032091b447f054b065b1ff7e647b3768221384f26f171c35ff
My advise :