What is the most effective way to mitigate worm attacks?

Download security updates from the OS vendor and patch all vulnerable systems promptly.

The most effective mitigation is to:

1. Download security updates from the operating system vendor
2. Patch all vulnerable systems promptly
3. Configure end systems to automatically download updates

Keeping current with the latest versions of antivirus software is also essential as new malware is released.

Go deeper:

• Malware — Wikipedia — its prevention section explains why prompt patching is the key defence against self-spreading worms.