As reported by The Register, Google removed over 11 million .co.cc subdomain from its search index, since the company considered too many of the sites “spammy”. Free .co.cc subdomains are offered by a Korean company. The company also offers bulk registrations of 15,000 subdomains for a fee of $1,000. According to the company’s website they have 11,397,608 subdomains registered in 5,738,580 accounts.

Google classes the firm as a “freehost”, and has exercised its right to block the whole domain “if we see a very large fraction of sites on a specific freehost are spammy or low-quality”, according to Matt Cutts, head of Google’s web spam team.

The company said in a recent blog post: “To help protect users we recently modified those [malware-scanning] systems to identify bulk subdomain services which are being abused. In some severe cases our systems may now flag the whole bulk domain.”

The Anti-Phishing Working Group reported (PDF) 4,963 phishing attacks origination from co.cc domains in the second half of 2010.