The attackers have posted some data that was stolen from the company website during the attack and are said to be demanding a ransom of 750 bitcoin which is about US$13.8 million.
An Advantech spokesperson told iTWire in response to a request for comment: "Some data may have been stolen by hackers due to a small number of Advantech servers which were attacked.
"According to our internal risk evaluation, the stolen data was confidential, but only contained low-value documents.
A screenshot of the Windows Conti ransomware site on the dark web. Supplied
Advantech reported revenue of US$1.8 billion (A$2.43 billion) in 2019.
The spokesperson added: "At the same time, Advantech has also carried out data preservation and system upgrades related to customer information security and operating systems.
"Some media reported that Advantech was blackmailed, which is in line with the purpose of most general cyber attacks. Advantech will not be commenting on this.
"While resolving this incident, Advantech has introduced new detection, protection, and response actions into our cyber security strategies to mitigate risks of future attacks.
"We hope that our global colleagues, partners, and customers remain patient throughout the recovery period as we overcome this major cyber attack setback."