A prolific hacking group known as Cl0p claimed on Wednesday it had stolen large volumes of data from nearly 50 companies worldwide, including energy giant Shell, medical equipment maker Philips, industrial conglomerate GE and financial services firm Fiserv, according to a posting on the group's website.

Shell said it was aware of a recent "possible incident" and was investigating with security teams. Philips said it had "identified and contained an attempted cybersecurity compromise of a specific enterprise server related to internal data", adding the breach did not affect customer environments. Fiserv said it had found no evidence that customer, banking, transaction or personal data had been compromised.

Reuters could not independently verify the hacking group's claims about what data was stolen or how much, Channel NewsAsia business reports.