Marcin Kleczynski


Marcin Kleczynski is the CEO and co-founder of Malwarebytes. He programmed the first prototype of our free virus scanner when he was 14 years old. In 2004, Malwarebytes was launched and the rest is history.

20 years later, the basic version of Malwarebytes is still free.




“I needed a program that could get rid of the infection, so with the help of some friends, I built one myself.” 

Marcin Kleczynski is the CEO and co-founder of Malwarebytes, a global cybersecurity leader delivering award-winning device protection, identity and privacy solutions trusted by millions of people around the world. Marcin believes that a secure digital life is a human right regardless of who you are or the size of your wallet. He has driven Malwarebytes’ phenomenal growth from a free malware remediation scanner to a popular product suite nearing a billion downloads.  
When Marcin Kleczynski was 14 years old, he inadvertently infected his parents’ computer with malware while searching for video games online— despite having a popular antivirus program in place. He was determined to fix the problem himself, and eventually found help from community forums on the internet. The cumbersome process inspired Kleczynski to find a way to share his experience and solution. He set out to build a better way to take down malware and became a self-taught computer programmer in the process.  

It turned out I wasn’t the only one infected with malware, so I started giving away my program for free.

Kleczynski graduated with a Bachelor of Science degree from the University of Illinois, majoring in computer science, and built Malwarebytes from his college dorm room. By the time he was 18, the fledgling company had millions of dollars in sales.

Now, 20 years after Marcin’s gaming incident, Malwarebytes has evolved into a digital life protection platform, protecting individuals no matter their device or location. With a full suite of security, privacy, and identity solutions, Kleczynski remains committed to enabling digital life protection for all. Now in addition to the flagship free remediation scan, Malwarebytes offers free browser privacy, BrowserGuard, and free identity monitoring with the Digital Footprint Portal. 

Kleczynski continues to lead the strategic expansion of the business and the long-term vision for the Malwarebytes research and development teams. He was named one of Forbes Magazine’s ’30 Under 30′ Rising Stars of Enterprise Technology in 2015. In 2014, Kleczynski won the Silicon Valley Business Journal’s 40 Under 40 award, and the Ernst & Young Entrepreneur of the Year Award. 

Connect with Marcin on Twitter/X and LinkedIn