Information Security Stack Exchange is a question and answer site for information security professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

If you purchase an existing domain name that was already used by someone else what are the ways in which the domain could have been broken by the previous owner? Are such problems common and are there tools to detect them before purchasing a domain?

Two examples: An HTTP server serving the domain could have returned permanent redirect making a domain unusable for visitors that received the redirect until they clear browsers caches.

Similarly, a server could have returned HTTP "Strict-Transport-Security" header making a domain unusable over HTTP for visitors that received the header.

Any other examples?

share|improve this question
You might want to rephrase the question to make it very clear what you're asking. – Mark C. Wallace Dec 7 '12 at 11:45
up vote 30 down vote accepted

Some common risks to check:

Domain has Bad reputation - check for any existing negative online reviews for the domain.

Domain is Blocked in search results - Risk of search engine turning off the domain in its search results due to the previous content, malware etc.

Domain is Black listed - Domain on black lists such as Web of Trust and spam lists.

Sometimes the Way Back Machine can show you the domain history.


IP / Trademark infringement - the domain you purchased may infringe registered trademarks: consult your legal advisor before purchasing

share|improve this answer
Additionally, watch for stuff like email domain blacklists (rfc-ignorant and such). – Tom Marthenal Dec 13 '12 at 11:27

In addition to the ones mentioned already, the previous owner may have a SSL certificate that may still be valid. That would be a major issue especially for sites dealing with commerce.

share|improve this answer
Related question. – unor Mar 27 '14 at 13:50

I've figured out one more nasty trick: A long-term cached documents returned by the previous domain owner could be potentially used to steal cookies set by the new owner.

Say, GET returns an HTML document with cache expiration long in a future, and following content:

  1. JavaScript that reads all cookies and sends them to
  2. iframe that loads, so the page looks exactly like a normal index.html.

Now, when someone purchases, all cookies set by the new owner can be intercepted by the previous owner (of course only for visitors that visited when it belonged to the previous owner).

share|improve this answer
Is there a way we can prevent this from happening? – Mario Awad Dec 10 '12 at 19:24
@MarioAwad Not really. But it does depend on the user having visited the domain before you bought it, so its a fairly limited attack. – derobert Dec 11 '12 at 18:46

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.