From eScan Wiki
Q. How do we update eScan with the latest virus updates? </B>
A. eScan automatically keeps its virus database updated.
It checks for availability of the Internet connection. If it detects that Internet connectivity is present, it then checks to see if a new update is available.
If new updates are available, they are downloaded and implemented automatically.
The default frequency for update checks is currently set at 1-hour intervals, but can be manually configured for other periods as per the customer's requirements.