California-based semiconductor testing company reports ransomware attack to SEC

A semiconductor testing company warned regulators on Friday that its subsidiary in Singapore suffered a ransomware attack earlier this month. 

In a filing with the Securities and Exchange Commission last week, Trio-Tech International said the cyberattack was discovered on March 11 and led to the encryption of files within the subsidiary’s network. 

“At that time, management determined that the incident was not material,” the company said. “On March 18, 2026, the incident escalated and resulted in the unauthorized disclosure of certain Company data. Following this development, management concluded that the incident may constitute a material cybersecurity event.”. 

Trio-Tech International took its network offline and hired cybersecurity experts to deal with the attack after notifying law enforcement in Singapore. The company is still trying to restore systems. 

It is unclear what data was taken but the company said the subsidiary is “in the process of notifying affected parties.”

Founded in 1958, Trio-Tech International is involved in semiconductor testing, manufacturing and distribution.

It has offices in the U.S., Singapore, Malaysia, Thailand and China. The company is primarily hired to verify that semiconductor components meet or exceed the reliability standards demanded for automotive electronics, industrial electronics, computing and data storage, consumer electronics and communication markets.

The company said the full scope of the ransomware attack is still unknown and it may have an impact on the company’s finances. Trio-Tech International reported more than $36 million in revenue last year, with 94% of its customers located in Asia. It has about 600 employees, most of whom are located across Asia. 

The incident comes a month after another semiconductor test equipment supplier, Advantest, reported a ransomware attack to Japanese authorities. 

Ransomware gangs have repeatedly targeted the lucrative semiconductor industry over the last five years. Microchip Technology, one of the largest American semiconductor manufacturers, was attacked by the Play ransomware gang in 2024 while Applied Materials was hit in 2023. 

Chinese-owned semiconductor company Nexperia and Taiwan’s Foxsemicon both experienced ransomware attacks.