At the moment, 80 percent of affected systems have been recovered and TSMC says it "expects full recovery on August 6".
TSMC fabricates chip solutions for Apple and other mobile device vendors, and has reportedly kicked off its shipments for the forthcoming iPhones and other new smartphone models.
"TSMC has been attacked by viruses before, but this is the first time a virus attack has affected our production lines", said CFO Lora Ho.
TSMC is the largest chipmaker in the world which supplies components to companies like Apple, Qualcomm, Nvidia, and ADM.
Fireball near Bologna airport after road crash explosion
Italian media reports that some people were injured by glass flying from windows shattered by the force of the explosion. Police said: "Due to an accident on the highway, an explosion occurred resulting in a fire at Via Marco Emilio Lepido".
One day of lost productivity might not seem like much, but for companies operating on TSMC's scale, any delay is cause for concern. After the virus got onto some of the factory computers, some of its fabrication tools had become infected. The company has restored output since then but said the incident would delay shipments, without specifying what customers will be affected. An Apple spokesperson didn't immediately respond to a request for comment on Sunday.
A bellwether for the chip industry as well as an early indicator of iPhone demand, TSMC heads into its busiest quarters grappling with waning enthusiasm for the high-powered chips used to mine digital currencies.
Over the weekend the Company disclosed that a computer virus was affecting part of its production and that it is expected to impact 3% of its third-quarter 2018 revenues. "I was shocked and surprised", he told reporters in Taipei, adding that the company had enhanced its information security systems and protective measures. Analysts are still calling for more clarity on the situation, however, considering TSMC's description of the incident to be too vague even with data integrity supposedly intact. To the big questions concerning the financial impact of the virus attack, and the production impact, the TSMC representative was reticent to answer.