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Attacks/Breaches

4/4/2011
04:35 PM
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'Comodo Hacker' Says He Acted Alone

The plot thickens: In an effort to back up his claims, alleged hacker dumps apparent evidence of pilfered database from breached Comodo reseller, as well as Mozilla add-on site certificate

Comodo, a website certificate authority, revealed that nine SSL certificates were issued for fraudulent websites posing as domains for high-profile sites. Security researchers hope the incident will call attention to a certificate process they say is riddled with holes.

The certificates were issued for mail.google.com, www.google.com, login. skype.com, addons.mozilla. org, login.live.com, and global trustee, and three different ones for login.yahoo .com, according to Comodo. They can be used to impersonate Google, Yahoo, Skype, Microsoft, and Mozilla and to wage man-in-the-middle attacks, in which an attacker listens in on communications, such as Skype calls. The Mozilla certificate could let attackers establish a phony Firefox update that downloads malicious code to Firefox browsers fooled by its "certified" domain.

The incident started with the hack of one of Comodo's European resellers, which validates and issues SSL certificate requests. The attackers used stolen credentials from the reseller authority to issue the rogue certificates, which were revoked by Comodo once discovered. Comodo says there has been no sign of the certificates being used, and that its own root keys, intermediate certificate authorities, and hardware weren't compromised. Browsers with the Online Certificate Status Protocol feature will automatically block the certificates.

Whodunnit

The situation took another twist when someone claiming to be a 21-year-old Iranian hacker said he attacked the Comodo reseller, which he named as GlobalTrust. When critics questioned the ability of a lone hacker to pull this off, he fired back by posting what appears to be the reseller's database of 800 encrypted passwords.

Rambling manifestos by the alleged hacker posted on Pastebin, much of it in broken English, raise more questions and appear to shoot down Comodo's claim that the attack might be nation-state sponsored, most likely out of Iran, since the IP addresses involved came from that country.

"This could be a smokescreen trying to make it look like a lone gunman," says Mikko Hypponen, chief research officer of F-Secure. "Whoever posted it to Pastebin did have access to those original systems, so whoever is behind the posts was also behind the actual attack."

Regardless of who did it, security experts say the rogue certificates could still be in use, possibly in stealthy, one-off attack scenarios. "The scary thing is that it's hard to detect if they are still out there," says Mike Zusman, managing principal consultant at Intrepidus Group, who demonstrated similar attacks nearly two years ago at DefCon. Attackers wouldn't leave a certificate sitting on the Internet so that anyone could locate it, but instead "would use it in very targeted, specific attacks against one user or a subset of users," Zusman says.

The attack has put the certificate authority registration process under scrutiny again. "This is obviously a very serious case," says Hypponen, adding that he'd love to see it as a wake-up call for certificate authorities to shore up their systems, and for browser vendors to carefully look at their resellers.

Comodo's model of leaving resellers free to issue certificates without Comodo's validation left the door open for abuse. The bad guys had free rein, Hypponen says.

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