"Revil" software is thought to be at the origin of the recent hacking attack which forced three Cactus stores to close for several days.

According to Cyble, a platform in the cyber crime sector, the hackers have used ransomware to download confidential information from the group.

Thus far, the group has been subjected to a data leak as a warning, with the aim of forcing the group to meet the hackers' demands. In the event Cactus do not comply, the hackers have threatened to release more sensitive data.

Stores in Windhof, Bonnevoie and Merl were forced to close for several days over the weekend, while Cactus have submitted a complaint.