Holidays Bring an Increase in Spam Attacks

From: GroupWeb EmailWire.Com
Published: Fri Nov 18 2005

Southfield, MI -- Southfield Michigan -- This won’t surprise anyone but spammer attacks are on the rise. Computer Mail Services, Inc. (CMS), an expert in spam and email security, has been tracking Reverse Non-Delivery Reply (RNDR) attacks and the trend is upward as the holiday season approaches.

"We’ve seen a 230% rise in RNDR traffic in the last 30 days" says Alan A. Sitek, VP Development at CMS, "and with Thanksgiving approaching, this increase perfectly coincides with the holidays, a time when spam volume is expected to rise further".

In an RNDR attack, spammers use SMTP mail servers that are compliant to the specifications requiring the return of a non-delivery report (NDR). This NDR message goes to the forged sender of the undeliverable message, the intended spam victim.

An RNDR attack typically avoids filters built into many antispam solutions and results in thousands of messages to fictitious addresses being sent to your domain. Spammers know that the contents of the original spam email are returned to actual email addresses.

Vulnerable mail servers will spend their resources trying to deliver the NDRs and, if under heavy attack, normal mail delivery will slow. Beyond this RNDR attacks bring the risk of the domain being blacklisted.

"When fighting RNDR attacks, be aware that some antispam products don’t work 100% correctly", says Sitek, "and worse, their solutions open the door to Directory Harvest Attacks, a variant of RNDR. That’s where our Praetor product is different. It works correctly and completely".

RNDR, a form of indirect mail relay, was originally announced by CMS in a June 4, 2003 in a public warning.


Founded in 1982, Southfield, Michigan-based Computer Mail Services, Inc. (CMS) is a privately held company with expertise in the development of messaging related products. The company’s Praetor product protects mail servers of thousands of organizations worldwide

Praetor is a registered trademark of Computer Mail Services, Inc.

Computer Mail Services, Inc.
Lih-Tah Wong
Tel: 248-352-6700 x.210

This press release was issued through GroupWeb EmailWire.Com.
Company: GroupWeb EmailWire.Com

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