Ruing Java applet in IE will download "securitypack.jar"

My computer is not coecting to the Inteet. And we have an Intranet website which requires Java applet.

It is found that whenever I enter the Intranet website, the Java console states that it is trying to download "securitypack.jar" from the Inteet:

network: Checking for update at: https://javadl-esd-secure.oracle.com/update/securitypack.jar

May I ask what is this "securitypack.jar" for? Is there anyway to disable Java from downloading this "securitypack.jar", but still allow the conceed Java applet to run?

Thank you very much in advance.