Centos – clamav can’t find viruses in rar files on centos 6.4

I use ClamAV 0.97.8/17494 on CentOS 6.4. It's good but can't find viruses in rar files. It can detect same virus file as it is or in a zip file but in rar file ClamAV reports no virus.

ScanArchive=yes option is already enabled

I searched a lot on google but couldn't find a solution.

Does anyone know if there is a fix for this?

EDIT 1

Package unrar-4.2.3-1.el6.rf.i686 already installed and latest version

EDIT 2

ClamAV was installed using yum install clamav clamd

#ldd $(which clamscan)
linux-gate.so.1 =>  (0x008fb000)
libclamav.so.6 => /usr/lib/libclamav.so.6 (0x0051a000)
libpthread.so.0 => /lib/libpthread.so.0 (0x00ddc000)
libc.so.6 => /lib/libc.so.6 (0x002d3000)
libz.so.1 => /lib/libz.so.1 (0x00490000)
libbz2.so.1 => /lib/libbz2.so.1 (0x00dc3000)
libm.so.6 => /lib/libm.so.6 (0x004a6000)
libdl.so.2 => /lib/libdl.so.2 (0x00489000)
/lib/ld-linux.so.2 (0x002ad000)