I try to clean up w32.downadup.b by using
1 - delete unreconized schedule (all of it name like this : At1 , At2 .... which call rundll32.exe , ... )
2 - symantec removal tool
3 - after restart then update ms security patch
4- scan with symantec antivirus
it still can not fixed . please guide me the way or tool to remove this threat !
(Note: os in my network: window 2003, 2000 and xp)