The Atlanta-based group confirmed in September that 145.5mln customers had their accounts hacked earlier this year in one of the biggest cyber-attacks in history.
Equifax warned yesterday that it may have been targeted once again after it was forced to shut down one of its customer help online pages to investigate a possible breach, sending the share price plummeting.
But the stock has picked up in pre-market trade after a spokesman confirmed to CNBC late on Thursday that no evidence of a second hack had been found.
“Equifax can confirm that its systems were not compromised and that the reported issue did not affect our consumer online dispute portal.”
They added: “The issue involves a third-party vendor that Equifax uses to collect website performance data, and that vendor's code running on an Equifax website was serving malicious content.
“Since we learned of the issue, the vendor's code was removed from the webpage and we have taken the webpage offline to conduct further analysis.”
Shares gained 1.1% to US$108.81.