News Stay informed about the latest enterprise technology news and product updates.

UGNazi hacker group claims responsibility for Twitter outage

Hacktivist group UGNazi says it caused multiple Twitter outages Thursday. Update: Twitter says a "cascading bug" was to blame.

A hacker claiming affiliation with the Underground Nazi Hacktivist Group (UGNazi) has claimed responsibility for a two-hour Twitter outage this morning.

We took down Twitter for 2 hours this morning, one of the reasons being they support the CISPA bill and we wanted to show what we are capable of.

Cosmo, alleged hacker, in an email to

In an email exchange with, the hacker, calling herself “Cosmo,” said UGNazi conducted a denial-of-service attack against the social networking site because of Twitter’s support for the Cyber Intelligence Sharing and Protection Act (CISPA). The CISPA bill is the controversial proposed legislation that would facilitate sharing of network traffic information and cybersecurity threat data between the U.S. government and the private sector.

A Twitter representative, however, denied there was an attack on the service. Robert Weeks, a communications associate at Twitter, wrote in an email to “Regarding an attack: No.” and pointed to a Twitter status on the Twitter Communications account that read: "Today's outage is due to a cascaded bug in one of our infrastructure components."

The company followed up with an incident recap on its blog, posted at 4:26 p.m. PDT Thursday. "A 'cascading bug' is a bug with an effect that isn’t confined to a particular software element, but rather its effect 'cascades' into other elements as well," wrote Mazen Rawashdeh, Twitter's vice president of engineering. "One of the characteristics of such a bug is that it can have a significant impact on all users, worldwide, which was the case today. As soon as we discovered it, we took corrective actions, which included rolling back to a previous stable version of Twitter."

Internet tracking site Pingdom recorded five separate Twitter outages today, the first between 11:59 a.m. and 1:08 p.m. ET, another between 1:42 p.m. and 2:06 p.m. ET, a third between 2:42 p.m. and 2:59 p.m. ET, and two short outages between 4 and 4:30 p.m. ET.

Users trying to access Twitter during the outages received error messages that their requests had timed out, not the site’s iconic Fail Whale, which normally comes up when the site is not accessible.

Widely believed to be an offshoot of the former Lulzsec hacking group, UGNazi has claimed responsibility for a number of politically and socially motivated attacks against high-profile targets, such as Google, BP,, the Wounded Warrior Project, Comcast and, as well as the recent CloudFlare security breach, for a variety of reasons, including support of CISPA and SOPA, high gas prices, and claims of effective Internet security by software companies and Internet service providers.

“Cosmo” is listed on the UGNazi home page as a member. According to the site, her name is Hannah Sweet, but it’s unclear if this name is an alias as well. Softpedia reported that Cosmo was arrested May 21 for her involvement in a breach of WHMCS, a company that offers client management and billing products. The hackers reportedly stole 1.7 GB of data, including 500,000 usernames, passwords and some credit card data. All of the company’s files were deleted from the breached server, Softpedia reported.

“We took down Twitter for 2 hours this morning, one of the reasons being they support the CISPA bill and we wanted to show what we are capable of,” Cosmo wrote. “We are a known hacker group and we do not lie about our claims.”

Dig Deeper on Hacker tools and techniques: Underground hacking sites

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.