What is "bagle"

Bagle (also known as Beagle) is a mass-mailing computer worm affecting all versions of Microsoft Windows. The first strain, Bagle.A, did not propagate widely. A second variant, Bagle.B, is considerably more virulent.

Bagle uses its own SMTP engine to mass-mail itself as an attachment to recipients gathered from the infected computer. It copies itself to the Windows system directory (Bagle.A as bbeagle.exe, Bagle.B as au.exe) and opens a backdoor on TCP port 6777 (Bagle.A) or 8866 (Bagle.B). It does not mail itself to addresses containing certain strings such as "@hotmail.com", "@msn.com", "@microsoft" or "@avp".

The initial strain, Bagle.A, was first sighted on January 18, 2004. It was not widespread and stopped spreading after January 28, 2004.

The second strain, Bagle.B, was first sighted on February 17, 2004. It was much more widespread and appeared in large numbers; Network Associates rated it a "medium" threat. It is designed to stop spreading after February 25, 2004.

Subsequent variants have later been discovered. Although they have not all been successful, a number remain notable threats.

Some of these variants contain the text

"Greetz to antivirus companies
In a difficult world,
In a nameless time,
I want to survive,
So, you will be mine!!
-- Bagle Author, 29.04.04, Germany."

Which makes some people think the worm originated in Germany.

Since 2004, the threat risk from these variants has been changed to "low" due to decreased prevalence. However, Windows users are warned to watch out for it.

Bagle may refer to:

• Bagle (computer worm)