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Install rootkit hunter (http://www.rootkit.nl/projects/rootkit_hunter.html)

wget http://superb-east.dl.sourceforge.net/sourceforge/rkhunter/rkhunter-1.2.9.tar.gz
sh ./installer.sh

run:
rkhunter –update
rkhunter -c

if it can’t find the OS, then run
Install hashupd (http://www.rootshell.be/~unspawn/hashupd.sh.gz)
hashupd -m

Then
rkhunter -c –quiet –cronjob

Should report no errors, add the above command to cron

# run rkhunter
0 0 * * * /usr/local/bin/rkhunter –versioncheck –quiet
1 0 * * * /usr/local/bin/rkhunter –update >/dev/null
5 0 * * * /usr/local/bin/rkhunter -c –quiet –cronjob