ISNSYS.dll definition, relationships, removal:

iSpyNOW Keylogger. ISNSYS.dll is located in "C:\Program Files\iSpyNOW". File isnsys.dll is related to Advanced Logger DLL. isnsys.dll is a dynamically linked library. In simple phrase, it is an essential component of a particular parasite. Most threats depend on such libraries and wouldn't work without them. The isnsys.dll file can be responsible for the dangerous payload a parasite carries, so deleting it will definitely reduce all the security and privacy risks.
The isnsys.dll file is installed and used by Chast.
In most cases isnsys.dll is responsible for all the harmful actions the pest takes. Removing this file will immediately terminate the parasite or partially disable it. That is why the isnsys.dll file must be manually deleted. If you cannot erase it, consider using recommended spyware removers, which will get rid of isnsys.dll and associated parasites for you.
Sometimes a presence of isnsys.dll does not indicate that your computer is infected. It can be an essential system file or a file installed by harmless legitimate software and therefore may not pose any threat to your privacy and the system. Although such cases are quite rare, you should thoroughly examine isnsys.dll before completely deleting or leaving it in the system.