Cannot open shared object: when starting nrpe

Got this error when starting nrpe

Starting nagios-nrpe: nagios-nrpe/usr/sbin/nrpe: error while loading shared libraries: libssl.so.0.9.8:

Pls advise

---------- Post updated at 04:05 PM ---------- Previous update was at 04:05 PM ----------

os is Debian lenny

---------- Post updated at 04:11 PM ---------- Previous update was at 04:05 PM ----------

how can I install this manually because cannot use apt-get install anymore since my os is lenny