VBS.Gaggle.D is a mass-mailing worm that overwrites several files. This worm can infect the following files:
The worm retrieves email addresses from the files that have .hta, .htm, .html, .php, .shtm, .shtml, .phtm, .phtml, .mht, .mhtml, .plg, or .htx extensions. Then, it uses its own SMTP engine to send its archive to all the email addresses that it finds. The worm can also spread through mIRC, ICQ, and some file-sharing networks.
The From field of the email is spoofed, the subject line and message vary, and the attachment is Filezip.zip.
When the worm runs, it may display a picture of the (singer) Avril Lavigne.
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