Popular image hosting website Imgur notified users on Friday that hackers had stolen data associated with 1.7 million accounts as a result of a breach that occurred back in 2014.
The company learned about the hack from Australian security expert Troy Hunt, operator of the Have I Been Pwned breach notification service, and immediately began taking steps to address the situation.
“I want to recognise Imgur’s exemplary handling of this: that’s 25 hours and 10 mins from my initial email to a press address to them mobilising people over Thanksgiving, assessing the data, beginning password resets and making a public disclosure,” Hunt said.
Others also praised the company for the way it handled the incident, with many comparing it to Uber, which attempted to cover up a massive 2016 breach that hit more than 57 million users.
Only email addresses and passwords were apparently compromised in the Imgur breach and the company says it does not ask users to provide any other data, such as real names, addresses or phone numbers.
At the time of the hack, the passwords had been stored as hashes generated using the SHA-256 algorithm, which can be cracked. The MD5Decrypt service, for example, can reveal the plaintext password from an SHA-256 hash if it’s one of the 3.7 billion strings stored in its database. Imgur said it switched to the more secure bcrypt algorithm sometime last year.
Imgur is among the world’s largest 50 websites, with more than 150 million active users every month. In 2014, when the breach occurred, the site had roughly 130 million active monthly users. Some news articles describe these figures as “unique visitors,” which suggests that not all of these users have registered an account, especially since an account is not needed to view images posted on the website.
Nevertheless, it’s possible that the actual number of compromised accounts is much higher than 1.7 million. Hunt pointed out that the data he came across only appears to include passwords that were cracked. “I don’t know how much more data may have been originally obtained,” the expert said.
Hunt also noted that 60% of the compromised accounts had already been exposed in previous breaches tracked by Have I Been Pwned.
Imgur has notified affected users and is requiring them to change their passwords. The company’s investigation into this incident is ongoing.
“We take protection of your information very seriously and will be conducting an internal security review of our system and processes,” said Roy Sehgal, Chief Operating Officer of Imgur.
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