Run a full antivirus scan immediately. Then uninstall the software. The "serial number" is either:

Despite this reality, the search persists. Common reasons include:

Adobe Illustrator CC (Creative Cloud) launched in June 2013. CC 2015 (version 19.0) was released in June 2015. This version:

The short answer is .

This article explores the reality of "verified" serial numbers, the transition to the Creative Cloud model, and the safest ways to access Illustrator today. The Shift from Serial Numbers to Creative Cloud

If your only reason for wanting a “verified serial number” for CC 2015 is to avoid monthly fees, consider these alternatives: