is actually a method to exploit a security vulnerability in the Microsoft Virtual Machine that is stored in the java cache as a java-applet. The vulnerability arises as the ByteCode verifier in the Microsoft VM does not correctly check for the presence of certain malformed code when a java-applet is loaded. Attackers can exploit the vulnerability by creating malicious Java applets and inserting them into web pages that could be hosted on a web site or sent to users as an attachment. Trojan Exploit ByteVerify indicates that a Java applet - a malicious Java archive file (JAR) - was found on your system containing the exploit code.
When a browser runs an applet, the Java Runtime Environment (JRE) stores all the downloaded files into its cache directory for better performance. Microsoft stores the applets in the Temporary Internet Files. The Java.ByteVerify will typically arrive as a component of other malicious content. An attacker could use the compiled Java class file to execute other code...Notification of infection does not always indicate that a machine has been infected
; it only indicates that a program included the viral class file. This does not mean that it used the malicious functionality.
These malicious applets are designed to exploit vulnerabilities in the Microsoft VM (Microsoft Security Bulletin MS03-011). If you are using the Sun JVM as your default virtual machine, these malicious applets cannot cause any harm to your computer.
AVG, eTrust EZ Antivirus, Pest Patrol and others will find Java/ByteVerify but cannot get rid of them. If you have the Java-Plugin installed, then deleting them from the Java cache should eliminate the problem. The Java Plug-In in the Control Panel is only present if you are using Sun's Java. If you don't have the Java-Plugin installed then just delete the files manually. The Microsoft Virtual machine stores the applets in the Temporary Internet Files.
To read more about this vulnerability issue please see Microsoft Security Bulletin MS03-011
and MS Article ID: 816093