Executables and md5 checksum.

[Alexandre Strube]

Em Qua, 2004-01-14 às 11:02, Piotr Goczal mazurek escreveu:

> > Prelink can do this, but it wouldn't hurt if you scan your machine for
> > viruses ;-)
> All 7 machines? At the same time? Rather imposible. I've just scaned one
> of the machines with updated AVP and the newest chkrootkit. Nothing
> found.

Its always healthy to do that, so I said "it wouldn't hurt :-)"


> Extract md5sum from fresh downloaded coreutils-5.0-24.i386.rpm

> [root at pc-bilbo tym2]# md5sum ./md5sum
> 4d41d3ab42c0756c1b194583e11c7d87  ./md5sum
> [root at pc-bilbo tym2]# md5sum /usr/bin/md5sum
> 1d0d6179faeda790c5305712d63f4fbf  /usr/bin/md5sum
> [root at pc-bilbo tym2]# cp ./md5sum /usr/bin/md5sum
> cp: overwrite `/usr/bin/md5sum'? y
> [root at pc-bilbo tym2]# md5sum /usr/bin/md5sum
> 4d41d3ab42c0756c1b194583e11c7d87  /usr/bin/md5sum
> [root at pc-bilbo tym2]# /etc/cron.daily/prelink
> INIT: version 2.85 reloading
> [root at pc-bilbo tym2]# md5sum /usr/bin/md5sum
> 1d0d6179faeda790c5305712d63f4fbf  /usr/bin/md5sum
> and YES I've found the virus :-). It's called prelink.
> Could anyone tell me what EXACTLY prelink does?

As stated in its name, prelink 'links' the shared libraries with the
executable, which uses to be done at runtime, as this linking does not
change very often. This speeds application opening. I've read somewhere
that prelink can speed a kde app's startup in a factor of 2... What
means, reducing loading time to 50% (I remember this exact example of
kde, though I don't use it).

-- 
[]s

Alexandre Ganso 
500 FOUR vermelha - Diretor Steel Goose Moto Group