Yahoo Attacked By Yamanner Worm

Dennis Faas's picture

Yahoo Mail, the world's most popular e-mail service, was recently attacked by a software virus (worm) dubbed "Yamanner" or "JS.Yamanner."

Major anti-virus companies Trend Micro and McAfee disagree with Symantec (Norton) about Yamanner's threat level. Trend Micro and McAfee have categorized the virus as a "low" threat, but Symantec (Norton) is calling it an "elevated threat."

Most worms are activated only after an infected e-mail file attachment is downloaded. Not Yamanner. Merely opening the mail is enough to automatically unleash the virus onto your computer. That is likely the reason for Symantec's higher danger ranking. (Source:

E-mails containing the worm can be identified by the following subject header and contents:

From: <blank>
Subject: New Graphic Site
Body: this is test

If you are a Yahoo Mail user, these are the steps you can take to protect yourself:

1) Make sure your anti-virus and firewall programs are up-to-date.

2) Do not open any e-mails that match what has been described above.

3) Block the e-mail address

4) Firewalls should be set to block all outbound traffic to (it is recommended that you do not visit this website).

Yahoo Mail Beta Users Not Affected by Worm

Yahoo is presently working on the next version of its Yahoo Mail service, currently dubbed "Yahoo Mail Beta." Some Yahoo Mail users already have access to the Beta Service. According to Symantec, users of Yahoo Mail Beta will not be affected by the worm, but regular Yahoo Mail users remain vulnerable. (Source:

Yahoo is now claiming that the virus has been contained:

"We have taken steps to resolve the issue and protect our users from further attacks of this worm," stated Yahoo spokesperson Kelley Podboy. "The solution has been automatically distributed to all Yahoo Mail customers, and requires no additional action on the part of the user." (Source:

As of this writing, the e-mail solution promised by Yahoo has not been delivered to any of my five Yahoo Mail addresses.

For now, the only guaranteed way to stay safe is to follow the steps outlined above.

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