Ransomware Attack Hits Diamond Electric’s Thai Subsidiary

Diamond Electric Holdings has confirmed that its Thai subsidiary, Thai Diamond & Zebra Electric, suffered a ransomware attack earlier this month. The company is now investigating the scope of the damage, including whether any sensitive information was leaked.

Attack Details

On September 8, 2025, at around 11 a.m., local servers and several devices used by the subsidiary were found encrypted by ransomware. Immediately after detection, the company disconnected external networks and halted the use of compromised systems to contain the spread.

Response and Recovery Efforts

From September 9, the subsidiary began working with external cybersecurity experts to analyze the incident, identify the root cause, and initiate recovery. Measures include:

• Checking for possible data leaks
• Investigating the attack route
• Restoring affected systems

The company has also strengthened its monitoring systems to prevent future incidents.

Customer and Regulatory Communication

Diamond Electric Holdings has been notifying affected customers individually. It is also cooperating with local authorities and law enforcement in Thailand as part of the official response.

No Impact on Other Group Companies

At this stage, the company reports that the cyberattack is limited to the Thai subsidiary only. Other group companies, including Diamond Electric itself, have not been affected.