On Thursday morning, the hacker group known as “OurMine” hijacked several Medium blogs-including a Fortune contributors network. The group hit Wired’s Backchannel site and, we believe, a Bloomberg Tech blog, too.
Medium’s team took the sites down soon after being notified, eventually regaining control and restoring their content.
The hacker (or hackers) had taken over the Medium account of an employee on the blogging site’s strategic partnerships team, which works with publishers such as Fortune and Bloomberg, a person involved in the cleanup told Fortune. During the attack, OurMine used its access to do what it usually does: deface the sites, blast notices that they had been hacked, and claim to be “testing” security.
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“Hacked By OurMine ( Read Important! ) Hacked By OurMine ( Read Important! ),” the group posted on Backchannel. A screenshot of the text captured in Google’s search engine cache following the takeover can be seen below.
“We’re temporarily offline-thanks for bearing with us while we sort things out!” Backchannel posted on Twitter in the interim. (This site and the others are now back online.)
The vandals did the same to a Fortune’s “insiders” blog, which is independent from the website you’re currently reading. “Hacked By OurMine,” the group wrote on the Medium page, changing the content of existing posts. “Hi, it’s OurMine don’t worry we are just testing your security,” the group said, before directing people to the its own website. (We do not recommend visiting their site.)
Fortune believes the hackers also targeted Bloomberg Tech’s Medium page. Like Fortune’s and Backchannel’s pages, Bloomberg’s homepage displayed a “404” error message shortly after the takeovers came to light. A Bloomberg spokesperson declined to comment.
In a statement provided to Fortune, Medium confirmed the hack. “This morning a group claiming to be OurMine gained access to a few publications that are hosted on Medium.com and made several changes to their content,” the company wrote. “We have stemmed all unauthorized access to these publications and halted the hack. We have reached out to all impacted publications to revert their sites to their previous state.”
According to a spokesperson from Backchannel, the OurMine vandals replaced the content of three stories and hacked the site’s homepage, resulting in the site being offline for about an hour.
A source familiar with the matter said Thursday’s incidents stemmed from OurMine hacking the Twitter twtr account of a Medium administrator. The employee also used the Twitter account as a log-in mechanism for the online publication platform, which let the hacker access the publishers’ pages on Medium.