New Code Red variant raising alarms

A new version of the Code Red worm is spreading on the Internet, more than 18 months after the original worm infected Web servers worldwide, according to alerts posted Wednesday by a number of antivirus software vendors.

The new version, labeled CodeRed.F, is almost identical to another Code Red variant, CodeRed.C, also known as Code Red II, according to information posted by F-Secure Corp. of Helsinki, Finland.

Code Red II first appeared about a month after the first worm, in August of 2001, and took advantage of the same Microsoft Corp. Internet Information Server (IIS) security flaw that the first Code Red worm exploited, but took the added step of installing a back door ("Trojan") program on the machines it infected, giving remote attackers total control of that system, F-Secure said.

Code Red worms use the IIS vulnerability to cause a buffer overflow on vulnerable Web servers. Once infected by Code Red, machines search for other vulnerable Web servers to infect.

The worm is programmed to spread for the first 19 days of each month, after which infected machines launch a day-long denial of service attack against the White House domain,, then shut off, according to F-Secure.

Changes in just two bytes of code distinguish CodeRed.F from the Code Red II variant. Those changes disable a feature of Code Red II that caused it to become dormant at the end of 2002, according to an alert posted by Computer Associates International Inc.

As a result, the CodeRed.F will be able to continue spreading almost indefinitely, with serious repercussions for network administrators, Computer Associates said.

As of Wednesday, however, most antivirus vendors rated CodeRed.F a low risk, noting that it treads the well-worn trail of previous Code Red variants, exploiting an IIS vulnerability that many system administrators have long since patched.

In addition, because of its similarity to Code Red II, many antivirus software packages will detect the new variant without requiring a new virus definition, according to Computer Associates and Symantec Corp.

The systems most likely to be affected by the new worm are home systems that are not protected by antivirus or firewall software and "forgotten Web servers," many of which are already infected by earlier versions of Code Red, according to F-Secure.

Administrators who are running vulnerable versions of IIS were strongly encouraged to secure those systems using patches available from Microsoft's Web site. (See or

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Paul Roberts

IDG News Service
Show Comments

Cool Tech

Bang and Olufsen Beosound Stage - Dolby Atmos Soundbar

Learn more >

Toys for Boys

ASUS ROG, ACRONYM partner for Special Edition Zephyrus G14

Learn more >

Sony WF-1000XM3 Wireless Noise Cancelling Headphones

Learn more >

Nakamichi Delta 100 3-Way Hi Fi Speaker System

Learn more >

Family Friendly

Philips Sonicare Diamond Clean 9000 Toothbrush

Learn more >

Mario Kart Live: Home Circuit for Nintendo Switch

Learn more >

Stocking Stuffer

SunnyBunny Snowflakes 20 LED Solar Powered Fairy String

Learn more >

Teac 7 inch Swivel Screen Portable DVD Player

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers


This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang


It really doesn’t get more “gaming laptop” than this.

Jack Jeffries


As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr


The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?