This weekend marks the 20th anniversary of the Internet Worm, the first major worm that propagated on the Internet. Even though many years have passed and underlying media has changed, worms are still able to wreak havoc and keep system administrators up at night. Today the damage done by worms is far less visible and far less newsworthy but far more difficult to repair than in the past.

On November 2nd, 1988, Robert Tappan Morris launched an application ostensibly designed to count the number of systems on the Internet. It was designed to propagate across Unix systems by exploiting several vulnerabilities, including a conceptual flaw in how r-services (rlogin, rsh, and rexec) authenticate connections, the archaic remote debug feature in Sendmail, and a buffer overflow in the finger daemon.

There was a flaw in its design, the Worm attempted far more propagation attempts than were necessary, causing targeted machines to slow dramatically from resource starvation. Long story short, the then Mr. Morris was caught, found guilty, and sentenced to probation and community service.

Many years of highly visible worms followed. Who could forget such classic hits as Melissa and I Love You, viruses that attacked software that is standard on Windows PCs, as well as Code Red and SQL Slammer for their Windows Server brethren.

Source: ZDNet