Topface Chief Executive Dmitry Filatov said the company located the hacker, who had published ads to sell the data but had not actually sold them.
"We have paid him an award for finding a vulnerability and agreed on further cooperation in the field of data security," Filatov said in an email on Friday, declining to disclose the size of the reward.
Topface says it has some 92 million users and 1.6 million daily visitors.
Cyber-security experts typically advise companies not to pay hackers to return stolen data, calling that a ransom and saying cybercriminals often break promises.
But Filatov noted that the ads have already been removed and Topface has agreed not to pursue charges against the unidentified individual.
"As we made an agreement with him we do not see any reason for him to break it," said Filatov.
Atlanta-based fraud protection firm Easy Solutions disclosed the hack on Sunday, reporting on its blog that a hacker known as "Mastermind" was attempting to sell 20 million credentials for an unnamed dating site.
The security firm had warned the credentials might be used to access accounts on other sites because people frequently use the same passwords for multiple accounts.
It said the data included 7 million credentials from Microsoft Corp's Hotmail service as well as 2.5 million from email accounts with Yahoo Inc and Google Inc .
Only email address had been stolen, Filatov said. "There was no access to other information - neither passwords, nor content of the accounts."
© Thomson Reuters 2015
Get your daily dose of tech news, reviews, and insights, in under 80 characters on Gadgets 360 Turbo. Connect with fellow tech lovers on our Forum. Follow us on X, Facebook, WhatsApp, Threads and Google News for instant updates. Catch all the action on our YouTube channel.
Samsung Galaxy Watch 9 (44mm, LTE)
Starts from ₹44,999
Samsung Galaxy Watch 9 (40mm, LTE)
Starts from ₹37,999
Samsung Galaxy Watch 9 (40mm)
Starts from ₹37,999
Haier M70 Mini LED 65-inch
Starts from ₹74,990
CMF Buds Neo True Wireless Stereo (TWS) Earphones
Starts from ₹2,199
Xiaomi TV FX Mini LED 65
Starts from ₹64,999
IFA 2026: Lenovo Unveiled New IdeaPad, Yoga and ThinkBook Laptops
IFA 2026: Nvidia RTX Spark PCs, Local AI Tools Announced With October Launch Planned
Luna Band Now Available Globally: Check Price in India, Specifications and Features