sample config file (e.g. winnow_bad_cw and various bofhland lists).
Comment-out MBL to disable by default, it has various problems with
false-positives and doesn't seem very effective at present.
The clamav-unofficial-sigs script provides a simple way to
download, test, and update third-party signature databases
for ClamAV provided by Sanesecurity, SecuriteInfo, INetMsg,
OITC, MalwarePatrol, and ScamNailer.