Microsoft and Japan Dismantle Cybercrime Network Behind Over a Billion Scam Messages

Microsoft has announced the dismantling of a significant cybercrime network, in partnership with Japan's National Police Agency. The operation targeted a marketplace known as YAM Store, along with associated phishing kits named CoGUI and Iron Man, which were instrumental in distributing malicious messages.

Since January 2026, the YAM Store network facilitated the sending of over one billion scam messages worldwide. These messages were directed at more than 75,000 organizations, with over 750 million specifically aimed at recipients globally. The scams commonly mimicked legitimate notifications, such as those for parking tickets or package deliveries, to deceive individuals.

According to Microsoft, YAM Store served as a crucial hub for cybercriminals, enabling them to deploy large-scale phishing campaigns. The collaboration between Microsoft and Japanese law enforcement aimed to disrupt these operations and prevent future attacks.

This action highlights ongoing efforts to combat cyber threats. Phishing continues to be a prevalent issue, and authorities stress the importance of user vigilance and cybersecurity measures to protect against such fraudulent activities.