Upcoming Events

Interop NY
Oct. 1-5

Interop is the only event to give you a comprehensive and unbiased understanding of all the latest innovations-including cloud computing, virtualization, security, mobility and data center advances-that help position your company for growth.

Register Now!

More Events »

Subscribe to Newsletter

  • Keep up with all of the latest news and analysis on the fast-moving IT industry with Network Computing newsletters.
Sign Up

Spammer Directory Harvest Attacks Hammer Enterprises

Tags: , , , , , , , , , , , , , ,

Channel: Other, Data Protection, UC & VoIP

Directory harvest attacks (DHAs) are the least visible, most under-reported threat to corporate e-mail systems, a study published Wednesday said.

DHAs are brute force attempts by spammers to find valid e-mail addresses where the spammer connects to business's e-mail server and guesses addresses until he gets some right. Those addresses are then harvested for use in later spam campaigns.

"DHAs are the silent kill of e-mail servers," said Chris Smith, the marketing director at anti-spam managed service provider Postini, and author of the Redwood City, Calif.-based firm's annual E-Mail Security Report.

"It's the most under-reported threat by far," said Smith. "The thing is, directory harvest attacks work, and they're how spammers are getting their spam addresses now. Plus they're difficult to defend against."

To illustrate the nature of DHAs, Smith cited data from Postini's efforts during 2004, in which it deflected an average of 150 DHAs per day per customer. Postini has some 5,000 corporate customers.


Page:  1 | 2 |3 |4 |Next Page »

Related Stories

Related Reading


More Insights




Currently we allow the following HTML tags in comments:

Single tags

These tags can be used alone and don't need an ending tag.

<br> Defines a single line break

<hr> Defines a horizontal line

Matching tags

These require an ending tag - e.g. <i>italic text</i>

<a> Defines an anchor

<b> Defines bold text

<big> Defines big text

<blockquote> Defines a long quotation

<caption> Defines a table caption

<cite> Defines a citation

<code> Defines computer code text

<em> Defines emphasized text

<fieldset> Defines a border around elements in a form

<h1> This is heading 1

<h2> This is heading 2

<h3> This is heading 3

<h4> This is heading 4

<h5> This is heading 5

<h6> This is heading 6

<i> Defines italic text

<p> Defines a paragraph

<pre> Defines preformatted text

<q> Defines a short quotation

<samp> Defines sample computer code text

<small> Defines small text

<span> Defines a section in a document

<s> Defines strikethrough text

<strike> Defines strikethrough text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

Network Computing encourages readers to engage in spirited, healthy debate, including taking us to task. However, Network Computing moderates all comments posted to our site, and reserves the right to modify or remove any content that it determines to be derogatory, offensive, inflammatory, vulgar, irrelevant/off-topic, racist or obvious marketing/SPAM. Network Computing further reserves the right to disable the profile of any commenter participating in said activities.

 
Disqus Tips To upload an avatar photo, first complete your Disqus profile. | View the list of supported HTML tags you can use to style comments. | Please read our commenting policy.
 

Research and Reports

Storage Virtualization Guide
May 2012

Network Computing: May 2012

TechWeb Careers