A computer virus takes down several Taiwan Semiconductor Manufacturing Co. factories. This represents one of the company’s most severe disruptions as it begins preparing chips for Apple’s next iPhones.

The sole maker of the iPhone’s main processor says that its fabrication tools were infected. The problem is now contained, with some of production ramping up. Still, many of its factories won’t open until Sunday at the least. The virus wasn’t introduced by a hacker, the company adds.

TSMC is the world’s biggest contract manufacturer of chips for companies like Apple and Qualcomm Inc. Currently, it’s unknown who the culprit is. Though this is the first time a virus has shut down a TSMC facility, it is reminiscent of the WannaCry cyberattacks in 2017. TSMC is working hard to solve the issue, but is complicated by varying degrees of infections from factory to factory.

“TSMC has been attacked by viruses before, but this is the first time a virus attack has affected our production lines,” Chief Financial Officer Lora Ho tells Bloomberg. She does not disclose the virus’ effect on revenue and lines producing iPhone chips.

It’s unknown how much this will affect Apple, as well. The iPhone maker last week surpassed a market value of $1 trillion thanks to its international iPhone sales. Still, this is an important time for tech companies as they ready their products for fall.

The company began manufacturing Apple’s A12 chip in May. The chip will appear in this year’s line of iPhones and will be the first to use a new 7nm process.

(Source: Bloomberg)