Foundry giant Taiwan Semiconductor Manufacturing Co. (TSMC) said a computer virus outbreak that hit the company on Aug. 3 will reduce its third quarter revenue by about 3%.

The virus, which TSMC said was accidentally spread by misoperation during the software installation process for a new tool, affected a number of the company's computer systems and fab tools in Taiwan. The company said Sunday that about 80% of the impacted tools had been recovered and that a full recovery is expected Monday.

TSMC (Hsinchu, Taiwan) said it expects the incident to cause shipment delays and additional costs that will not only hurt its third quarter revenue, also reduce its third quarter gross margin by about 1%. TSMC said it is confident shipments delayed in third quarter will be recovered in the fourth quarter and maintains its forecast of high single-digit revenue growth for 2018 issued last month.

Most of TSMC’s customers have been notified of this event, the company said.