Dive Brief: 

• Yahoo's ad servers have fallen victim to a malware attack. 
• The attack infected thousands of users in various European countries with malware after they visited Yahoo.com and were served a malicious ad. 
• According to estimations by Fox-IT, the malware was infecting around 27,000 users every hour, but Yahoo claims the malicious ad has been removed, so no further users should be affected. 

Dive Insight: 

Yahoo is one of several companies, like Snapchat and Target before it, that have suffered image-damaging security breaches in recent weeks. Yahoo has been under scrutiny since new CEO Marissa Mayers took her position and began drastic changes to the company. Ads have been a particular point of focus, so this breach could lead to a dip in Yahoo's traffic and also cause its ad revenue to suffer.