Beagle.AA is a mass-mailing worm. It has its own SMTP engine to spread through email and opens a backdoor on TCP port 1234.
The email has a variable subject and a file attachment. The attachment has .com, .cpl, .exe, .hta, .scr, .vbs, or .zip file extension.
The following systems are affected.
System performance degradation.
Use antivirus software to scan and clean the system.
Don't open suspicious email.