From Webpronews:

A Trojan Horse known as "Trojan.Offensive" Is
Running Around The Net

    "In its current incarnation, the Trojan horse arrives in an e-mail
message and appears to be an HTML document with a single hyperlinked word:
"Start." Recipients of the e-mail who click the link, however, will cause a
java-scriptprogram to run; that program will take advantage of a flaw in
Microsoft's Java Virtual Machine--software used to run programs written in
Sun Microsystems' Java language--to modify the system's registry."
Your computer's registry is vital to the running of your system. This
modification of your computer's registry will effectively kill it.