The FBI announced on Monday that it “dismantled” a global phishing operation, which allegedly helped hackers target more than 17,000 victims worldwide.

The website of the operation, known as W3LL, displayed a notice saying it has been seized by the FBI. The bureau said it worked with Indonesia’s police in the takedown operation, which resulted in the detention of the alleged W3LL developer — only identified as G.L. — and the seizure of “key domains.”

Cybercriminals could purchase the W3LL phishing kit for $500 to deploy fake versions of websites that mimicked the login pages of legitimate services, allowing the criminals to steal passwords and multi-factor authentication codes from victims. The phishing kit enabled cybercriminals to “attempt more than $20 million in fraud,” according to the FBI.

The W3LL online marketplace also allegedly allowed criminals to buy and sell stolen credentials and access to hacked systems, which “facilitated the sale of more than 25,000 compromised accounts,” said the FBI.

The FBI did not immediately respond to a request for comment, asking to provide more information.