The problem is that Netscape's implementation of Java did not adhere to Java Sandbox guidelines, which is basically designed to protect users from Java code.

There hasn't been a global solution yet to this problem. If hackers can shut down Yahoo!, they can shut down anything they want tomorrow.

Sasser is a successful and widely propagating worm with a somewhat benign impact to the end user. But people should absolutely remove it.

A master command wakes up the agents, identifies the target, and says go for it.

Chat is a conduit for distribution of malicious code. It's a way to distribute Trojans, and, in addition, users who don't know how to hide their IP address will reveal it during chat. On the Internet, chat is risky business.

Its transmission technique is somewhat similar to Melissa. Once launched, it downloads an executable backdoor program from one of four Web sites. That program, Win_bug6, steals passwords stored on that computer and sends them to an e-mail address in the Philippines.

Web sites get hacked so frequently, probably 50 a day, and if a hacker breaks into a Web site, they can easily change the code on the site, so that when users go to the site they think it's a legitimate Web site, and they will get infected.

Companies are under more pressure to develop new product functionality than they are to release secure software. Companies don't put enough effort into making their software more secure.

It's a serious risk, although the threat has not manifested itself, but it's brand new.