On Wednesday, digital certificate issuer Comodo released a security warning that its European affiliate had issued nine fraudulent SSL certificates. The certificates -- used by Web sites to confirm the identity of end users -- were issued without sufficient identity validation, and were apparently obtained by the government of Iran.

All certificates have been revoked by Comodo. They involve seven domains: Firefox extensions (addons.mozilla.org), Global Trustee, Gmail (mail.google.com), Google (www.google.com), Skype (login.skype.com), Windows Live including Hotmail (login.live.com), and Yahoo (login.yahoo.com -- 3 certificates).

Microsoft on Thursday said that as a result of the fraudulent SSL certificates, it had updated Windows to prevent them from being used. In addition, it said, "browsers which have enabled the Online Certificate Status Protocol (OCSP) will interactively validate these certificates and block them from being used."

What's the threat posed by real security certificates being issued to the wrong party? According to Microsoft, "these certificates may be used to spoof content, perform phishing attacks, or perform man-in-the-middle attacks against all Web browser users including users of Internet Explorer."

Or to gather intelligence. "If you are a government and able to control Internet routing within your country, you can reroute all, say, Skype users to [a] fake https://login.skype.com and collect their usernames and passwords, regardless of the SSL encryption seemingly in place," said Mikko Hypponen, chief research officer at F-Secure, in a blog post."Or you can read their email when they go to Yahoo, Gmail, or Hotmail. Even most geeks wouldn't notice this was going on."

Who would try to obtain fraudulent certificates? Comodo says that circumstantial evidence points to a state-backed operation run by Iran, due to the speed and accuracy of the operation, as well as the focus. "The perpetrator has focused simply on the communication infrastructure -- not the financial infrastructure as a typical cyber-criminal might," according to Comodo's incident report.

More clues: The one attack seen so far that used the fraudulent certificates targeted an ISP in Iran. Furthermore, looking at all of the issued certificates, "the domains targeted would be of greatest use to a government attempting surveillance of Internet use by dissident groups," said Comodo's Phillip Hallam-Baker in a blog post.

Then again, it could be a diversion. "While the involvement of two IP addresses assigned to Iranian ISPs is suggestive of an origin, this may be the result of an attacker attempting to lay a false trail," he said. But on the other hand, "the perpetrator can only make use of these certificates if it had control of the DNS infrastructure."

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