When i upload now my serv-u is seen as a backdoor by f-secure antivirus, what must i change in the so he don't find it?

i had te same problem
i downloaded the latest verion. patched it with a patcher (i tougth it was from orion)

then i hexed it. I replaced all servu strings with my own one krni386 etc ...
example you change everything into windodaemon (lol) then u got to rename the servudaemon.ini in windodaemon.ini yust dont forget tho add the dll's in your rootkit pakkage. To get rid of the uglu green U icon i used an iconchanger named resourcehacker.

i ran it to different online scanners and my norton coorperate. all clean. i never have seen my servu got deleted on an stro. never. period.

tip: dont change the icon into an skull or something lame. take an windows systemfile icon

I hope i helped u out. There is a lot of info on the forum here regarding hexing etc..

respect

yes after ya did the hexedit do a executable (EXE/DLL/etc...) compressor
on it and the file is more secure
and smaller

just hexedit it, pack with upx
done that with mine, no AV detects it