On January 25th, 2003 Slammer made it’s appearance rapidly, spreading to nearly 75,000 machines. Exploiting vulnerabilities in Microsoft’s SQL Server and MSDE database, the worm quickly attacked the buffer overflow holes in those products. Thousands of companies and organizations suffered massive downtime because of their reliance on MS SQL and unpatched machines. There were heavy slowdowns in internet traffic globally, even causing core internet routers to crash. To this day Slammer is considered the first high speed worm.
Slammer doubled in size every 8.5 seconds and infected more than 90% of the world’s vulnerable hosts within 10 minutes.