Posts tagged with “DNS spoofing”

Understanding PHARMING

Tuesday, 17 March, 2009

pharmingA follow up on my previous entry about Phishing, here comes another threat on the Net – Pharming. As discussed earlier, phishers bait potential users with genuine looking email to convince victims by taking action to expose critical or personal information. A typical example is an email requesting you to update your password or provide your bank account information. Or asking you to click on the link to update your data. Be aware that banks do not email their customers asking them to change their password or provide their PIN or confidential data. They have better and more secure communication channels to acquire those.

But here comes the joy, or the trouble in this case. Pharming attacks usually do not require convincing emails. It is also more wide-coverage than phishing. While phishing trick victims using a genuine looking emails or links, pharming goes deeper underground in planting a seed for its farm err, pharm?

Pharming cultivation

The technique used in Pharming is not new. In fact it had been around for long. The difference, however, is the intention. They want your identity or data. Pharming takes advantage of hacking DNS (Domain Name Server) such as cache poisoning, spoofing, and hijacking. Let’s see how this works.

How Pharming Works

How Pharming Works

  1. An attacker exploits vulnerabilities of a DNS. Using crafted responses or take advantage of a vulnerability, an attacker can poisoned the DNS cache and can change valid entries. Internally, a disgruntled engineer can even manipulate the host lookup on these servers. Externally, attackers can take advantage of the operating systems vulnerabilities.
  2. A user wants to go to a website securetoday.net and enter in the browser.
  3. The user’s computer queries the DNS to resolve the site. Now, DNS being poisoned resolved the site to the nefarious fake website and redirected to securetodat.net.
  4. User unaware of what happened thinks he is on the correct website.

Of course, the fake website has to be designed as close as possible to convince the victims that they are on the correct website. On the website, they can ask the user to login, provide confidential information, and more.
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