W97M/Afeto is a Word 97 worm, that uses Outlook to spread itself.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
The worm arrives in an attachent of an email message.
When an infected document is opened, the worm first checks the size of the active document. It the size is less that 200000 bytes, the worm searchs "C:" -drive for a file with ".jpg" extension. If such file is found, and its size is less than 50000 bytes, the worm attempts to insert the image to the active document.
Next the worm goes through Outlook's Sent Items folder. If there is more than two messages, the worm will take the recipient name of the first message. If the name is shorter than five characters, the name will be taken as it is, otherwise the worm will take five characters from the name starting from the second one. The resulting string will be used as an attachment name.
After that W97M/Afeto.A@mm will send upto eight mails. The worm goes trough the Sent Items folder, from second message to the ninth. It takes one message subject and body at the time, combines that to recipient of the previous message in the folder, attachs itself to the message and sends it. The original message will be deleted from the Sent Items folder.
At the same time the worm copies itself using the same name to the root of the following drives, if they are available: C:, D:, E:, F:, G:, H: and I:.
F-Secure Anti-Virus detects and disinfects this worm since November 30, 2000
Description Created: Analysis: Katrin Tocheva and Sami Rautiainen, F-Secure; November 2000