Houseparty denied it had been hacked... while miscreants were abusing its dot-com domain name infrastructure

Subdomain takeover possible, infosec bod points out

At the end of March, video chat app Houseparty, owned by Epic Games, responded to unsubstantiated reports that user accounts had been hacked – by offering a $1m bounty to anyone able to prove the rumors were part of a coordinated campaign to smear the company.

The developer said at the time it had no evidence of any link between Houseparty and claimed compromises of accounts at other services like Spotify, Netflix, and PayPal. And it insisted Houseparty accounts were secure.

While some tweets taking aim at Houseparty appear to be dubious, evidence of any smear campaign has yet to surface, and it appears the $1m bounty has not been awarded. The Register twice asked Houseparty to confirm this. Though we received a statement, no answer was provided to that particular question.

Nor was any bug bounty paid to security researcher Zach Edwards after he found that Houseparty's domain infrastructure had been hijacked and abused to distribute malicious content.

On March 31, Edwards, co-founder of web analytics biz Victory Medium, criticized the chat app maker via Twitter for the lack of Content Security Policy headers on a password reset page. He suspected there may be further security issues, and a week later he submitted a bug report to Epic Games' HackerOne security response program detailing over a dozen subdomains of thehousepartyapp.com that were serving malicious PDFs.

They looked like this:

http://nyc3-prod-worker-138-197-97-151.ms.thehousepartyapp.com/lib8/schafzucht.pdf?web=nyc3-prod-worker-138-197-97-151.ms.thehousepartyapp.com

In a series of Twitter DMs with The Register, Edwards explained that the criminal hacker group behind the malicious files appears to have been operating for almost two decades. He said they hijack subdomains and redirect users to websites promising free video streaming, ebooks, and downloads.

"They hijack subdomains with 'poisonPDFs' that are filled with SEO-rich content and other exploits, and push users into malicious redirects and scam websites," he said. "Houseparty’s authentication domain was hit by the group."

Edwards, who refers to the hacking group as the Pickaflick.com Crew, based on a domain the group appears to have used for past credit card scamming, plans to publish further details about the operation on Wednesday via Medium.

He said he submitted his findings to Epic Games' HackerOne security response program based on Houseparty's $1m smear-verification prize without expecting that he would actually get paid. Rather, he said, he's hoping to get the company to engage with the security community to help other organizations hit by this group.

"I believe the facts are clear that an organized hacker and credit card fraud network used Epic Games subdomains to launch attacks on users," he stated in his post. "And this group continues to orchestrate these attacks across the internet, and has for years."

Edwards has identified 8,440 sabotaged PDFs associated with the malware group on various other websites.

Edwards's post includes email messages purportedly from the Epic Games security team in response to his bug report. The emails deny there was any targeted compromise of company systems by a malicious party.

"We confirmed that is not the case, and that the subdomains in question were pointing to abandoned DNS records, which in turn were automatically inherited by a third-party which was hosting eBooks," the message says.

There was no compromise because the door, so to speak, was left open by old domain records no one had bothered to remove, records that pointed to an IP address no longer controlled by Houseparty.

As the Epic Games email explains, "A third party inherited the IP address that Houseparty formerly owned, the DNS record associated with that IP was never removed, which is why that subdomain still directed to the IP in question."

The Register understands that Houseparty views the issue as a website misconfiguration issue and has taken steps to fix its domain infrastructure.

Asked to comment on Edwards's claims, a Houseparty spokesperson said: "The world trusts Houseparty to connect them when they need it most and we won’t let them down. We received the individual's correspondence attempting to claim the bounty and thoroughly reviewed it to confirm that it was not founded. The individual has not provided a proof of concept for his theoretical bug, which is required by all bug bounty programs. The Houseparty app is safe for use on any mobile device and is protected by industry trusted encryption, so your data and your experience are protected." ®