Symbiosis: ClamAV can be a resource hog, and doesn't need to be running if it's not configured.
We've had a few Symbiosis users recently (with otherwise pretty quiet machines who are seeing issues with clamav hogging resources - CPU, disk and RAM.
This seems to be down to a memory leak in clamd, which after 150+ days of uptime chews up a significant amount of RAM, which can then cause freshclam to have problems allocating memory, leading to it chewing up CPU time and disk space as it writes
WARNING: [LibClamAV] mpool_malloc(): Can't allocate memory ([0-9]* bytes). to freshclam.log over and over until the disk is full, then starts consuming all the CPU time on the box.
Really, clamd doesn't need to even be running if its not configured to be used, and provides users a false sense of security if they see it running on the box but its not configured, however it may be worth an extra daily/weekly forced restart/reload of the service if it is being used, to clear out any memory leak issues.