“Attackers are exploiting a known vulnerability in Yahoo’s network to
launch brute force attacks against users’ Yahoo mail accounts. The
attackers are using hijacked mail accounts to send spam. The main Yahoo login page has mechanisms in place that protect accounts from brute force attacks, but the recent attacks have been exploiting a web
application (services) that automates the authentication process and does not have the attack protection in place.”
Users should choose strong password to stay SAFE.