Source: Sharecast
The announcement, which came just hours after the Mexico-based miner delivered its interim results, was made late on Tuesday evening after market's closed, with the company assuring that it took "response measures" immediately.
"The company's IT experts, in coordination with external specialists, are taking all measures to investigate and assess the scope of this incident," Fresnillo said.
All business units were able to continue their activities and no material operational or financial impact was experienced, it said.
"The company will provide a further update as and when appropriate. Fresnillo plc takes the issue of cyber security extremely seriously and will continue to fully investigate this incident and take all appropriate measures."
Fresnillo shares finished up 3.1% on Tuesday after the company said it was on track to meet full year guidance after strong second-quarter production.
Quarterly attributable silver production of rose 8.4% quarter-on-quarter to 14.6 million ounces, though gold production was down 7.7% to 130,000 ounces.