What Is SQL Slammer?

Understanding SQL Slammer

Have you ever wondered what SQL Slammer is? In this article, we will explore the ins and outs of SQL Slammer, a notorious computer worm that wreaked havoc on the internet back in 2003. By the end of this article, you’ll have a clear understanding of what SQL Slammer is and how it affected the online world.

What is SQL Slammer?

SQL Slammer, also known as W32.SQLExp.Worm, is a computer worm that targets Microsoft SQL Server databases. It was unleashed on the internet on January 25, 2003, and quickly became one of the fastest-spreading computer worms of its time. It exploited a vulnerability in Microsoft’s SQL Server software, allowing it to propagate rapidly and cause widespread disruption.

Now, let’s dive a bit deeper into how SQL Slammer went about its destructive ways.

The Spread of SQL Slammer

SQL Slammer was a simple yet highly effective worm. Once it infected a vulnerable system, it replicated itself and scanned the internet for other vulnerable servers to exploit. It did not require any action from users, such as downloading or opening an infected file, to spread.

Here’s how SQL Slammer spread so rapidly:

1. The worm randomly generated IP addresses, attempting to establish a connection on the SQL Server’s default port (UDP port 1434).
2. If the targeted server was vulnerable, it automatically sent a small packet of data to the vulnerable server, exploiting the SQL Server Resolution Service vulnerability.
3. The infected server then became a carrier and continued to spread the worm to other vulnerable servers, creating a self-propagating cycle.

The speed at which SQL Slammer spread was astonishing. Within just 10 minutes of its release, it had infected over 75,000 servers, causing widespread disruptions and slowdowns across the internet. Websites, email systems, and even critical infrastructure services were impacted by the worm’s rapid propagation.

Although the worm did not have any payload or malicious code other than self-replication, its sheer speed and volume of network traffic generated by the infected systems created enormous congestion. This congestion resulted in collateral damage, affecting the availability and performance of various online services.

Eventually, the propagation of SQL Slammer was mitigated through the efforts of security researchers and network administrators, but the impact it had on the internet was significant.

In conclusion, SQL Slammer was a highly disruptive computer worm that targeted Microsoft SQL Server databases. Its rapid spread was facilitated by a vulnerability in Microsoft’s SQL Server software. Although the worm did not have any specific malicious payload, its propagation caused widespread congestion and disruption across the internet.