It's unclear why Klue had not revoked the credential after the limited pilot, which hackers then used to breach a system holding keys for accessing customers' data.

More cybersecurity firms have disclosed the impact of the Klue supply chain attack as hackers threaten to release stolen data.

Huntress, HackerOne, Jamf, Recorded Future, and Tanium are among the cybersecurity companies that had data stolen following an earlier breach at market research firm Klue.