From eScan Wiki
Q.What is Proactive Scanning?
A. Proactive scanning is an intelligent method used by eScan to check if a file is suspicious or good.
All executable files, library files and driver files can be checked by proactive scanning. A signed file (signed by Verisign, for example) is always whitelisted by proactive engine.
eScan maintains its own whitelisted database (which is auto-updated, along with the signatures) in order to keep files which are exceptions.
This DB is constantly kept updated by MicroWorld.
Suspicious scanning is not 100% perfect - and thats the reason, it has to always work alongside with a malware scanner. There may be false-positives, and if one is found, MicroWorld updates its DB as soon as possible, to ensure that FPs are removed.