how could i deal with this worm ?
it’s probably a part of Autorun virus… you can send the file to www.virutstotal.com analysis and verify it 
Did avast miss it or did it detect it?
Did you run a full avast scanning?
As Maxx said it is likely to be part of autorun.inf search for its presence.
Hidden Files - Ensure that you have hidden files and folders enabled and disable hide system files in Windows Explorer, Tools, Folder Options, Hidden files and folders, see image.
If you do a forum search for the ntde1ect.com, whilst the name is different (I suspect it changes) I believe it it the same autorun.inf infection. Here are some of the hits from the search.
http://forum.avast.com/index.php?topic=30933.msg256821#msg256821
http://forum.avast.com/index.php?topic=30913.0
http://forum.avast.com/index.php?topic=30758.0
Are you sing a USB pen drive, if so that is the likely source of infection.
Please do the following steps in the order that they are posted. It is important that the .bat be ran first.
Download this file queerymountpoints.bat from the link below and save it to your desktop
http://cid-32d8666f4048075b.skydrive.live.com/browse.aspx/Malware%20files
Plug in your USB device and double click the .bat file you just downloaded to run it. A notepad entitled Mountpoints.txt will appear on your desktop when it has finished. Please include that file in your next reply.
Download ComboFix from Here or Here to your Desktop.
Double click combofix.exe and follow the prompts.
When finished, it shall produce a log for you. Post that log and a new HJT log in your next reply
Note: Do not mouseclick combofix’s window while its running. That may cause it to stall.
Click here to download HJTsetup.exe
[*]Save HJTsetup.exe to your desktop.
[*]Doubleclick on the HJTsetup.exe icon on your desktop.
[*]By default it will install to C:\Program Files\Hijack This.
[*]Continue to click Next in the setup dialogue boxes until you get to the Select Addition Tasks dialogue.
[*]Put a check by Create a desktop icon then click Next again.
[*]Continue to follow the rest of the prompts from there.
[*]At the final dialogue box click Finish and it will launch Hijack This.
[*]Click on the Do a system scan and save a logfile button. It will scan and the log should open in notepad.
[*]Click on “Edit > Select All” then click on “Edit > Copy” to copy the entire contents of the log.
[*]Come back here to this thread and Paste the log in your next reply.
[*]DO NOT have Hijack This fix anything yet. Most of what it finds will be harmless or even required.
You can either copy and paste the requested logs or attach them to your next reply. (copy and paste will require multiple posts)
mountpoint.txt
combofix log
HJT log
i do not if what i did is the correct way or not
1-i rename amvo0.dll to xxx , restart my pc , then delete xxx
2-delete all the harmful autorun.inf & n1deiect.com files
3-use this link to correct the folder option values
http://forum.avast.com/index.php?topic=30933.msg256821#msg256821
now the virus is not working at all