The WannaCry ransomware onslaught has overshadowed some of the other notable happenings this month, including the spectacular Google-themed phishing/spamming attack. Attackers have managed to exploit vulnerabilities in the SS7 protocol suite to bypass German banks two-factor authentication and drain their customers bank accounts. CSPs are moving towards Diameter Signaling to support LTE and 5G investments in order to keep up with demands for new and improved services and Internet of Things (IoT) services.
Source: https://www.helpnetsecurity.com/2017/05/19/ss7-security-issues/