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68,000 Open Recursive DNS Servers Behaving Maliciously; "This is a crime with few witnesses"

Reported today: "Researchers at Google Inc. and the Georgia Institute of Technology are studying a virtually undetectable form of attack that quietly controls where victims go on the Internet."

The Georgia Tech and Google researchers estimate that as many as 0.4%, or 68,000, open-recursive DNS servers are behaving maliciously, returning false answers to DNS queries. Unlike other DNS servers, open-recursive systems will answer all DNS lookup requests from any computer on the Internet, a feature that makes them particularly useful for hackers. They also estimate that another 2% of them provide questionable results.

Read full story: PC World

Related topics: Cyberattack, Cybercrime, DNS, Security

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Re: 68,000 Open Recursive DNS Servers Behaving Maliciously; "This is a crime with few witnesses" The Famous Brett Watson  –  Dec 11, 2007 5:55 PM PDT

The attack discussed in the article involves the use of malware to modify the resolver settings on the (Windows-based) victim system so that it queries a malicious DNS server. This is a more advanced form of the old trick where the "hosts" file is modified directly, and not an attack on DNS infrastructure or protocols.

Re: 68,000 Open Recursive DNS Servers Behaving Maliciously; "This is a crime with few witnesses" David A. Ulevitch  –  Dec 12, 2007 8:38 AM PDT

Yes, this is a poorly written report.  I think the data is probably good, but it's obscured by inaccuracies in the write-up which I told the authors about before it published.  None of the significant errors I pointed out were corrected.

Open recursive nameservers continue to NOT be a problem in this domain and people running mis-configured nameservers is.  The fact that they are open may be related to the misconfiguration, but it is not a problem in and of itself.

We're open, but not susceptible to these attacks.

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