In May 2013 the Russian-language hacking forum YouHack suffered a data breach that was later redistributed as part of a larger corpus of data. The breach exposed 107,000 forum members' email addresses, usernames, IP addresses and MD5 password hashes, most of which were unsalted. Forum posts also contained email address and password pairs belonging to other victims, bringing the total to 7.2 million unique email addresses. The compromised data includes email addresses, IP addresses, passwords and usernames. The breach was added to Have I Been Pwned on 11 Nov 2026. The source recommends changing any reused passwords immediately and enabling two-factor authentication wherever it is supported. 1