Why does ClamAV seem to be slower than other engines?

Due to certain engine-specific design factors, ClamAV is known to be one of the slower performing engines included in the MetaDefender Core system.

However, ClamAV’s slow scan speed is easily counterbalanced by its high detection rate, quality, and stability.

As a workaround for the slow scan time, users can change some settings on the actual engine as described below:

• Limiting the file size that the engine should process by changing “Max File Size”

• Disabling “PDF Deep Scan” also makes the PDF scan faster but the trade-off is less detection rate.