SO, my qnap stoped updating clamav after firmware update.
check: ldd /usr/local/bin/freshclam
if it seems to be missing som libs
fix:
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libclamav.so.9.0.2 /usr/lib/libclamav.so.9.0.2
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libclammspack.so.0.1.0 /usr/lib/libclammspack.so.0.1.0
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libclamunrar.so.9.0.2 /usr/lib/libclamunrar.so.9.0.2
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libclamunrar_iface.so.9.0.2 /usr/lib/libclamunrar_iface.so.9.0.2ldconfig
freshclam -u [nasuser]
link for info: https://forum.qnap.com/viewtopic.php?t=95649
Update [ 25-03-2022]:
Some additions where missing:
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libclamav.so.9.0.4 /usr/lib/libclamav.so.9
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libfreshclam.so.2.0.0 /usr/lib/libfreshclam.so.2
ln -s /share/CACHEDEV1_DATA/.antivirus/usr/lib/libcharset.so.1.0.0 /usr/lib/libcharset.so.1