They say the best offense is a good defense.

Tenable Network Security has taken $50 million in its first round of funding for its software that protects against cybercrime. The technology keeps its clients safe by identifying vulnerabilities with passive scanning, monitoring networks in real time, and configuration and compliance management.

TNS’s comprehensive platform identifies weaknesses in enterprise security networks before attackers can exploit them and manages these threats. Its flagship products are Nessus and SecurityCenter.

Nessus, dubbed “The Swiss Army Knife of vulnerability assessment,” continuously seeks out risks by scanning IT infrastructures for security flaws and compliance issues. SecurityCenter collects, analyzes, and communicates threats from a central hub to keep vulnerabilities under control.

Security is a major concern for any enterprise that wants to keep its data safe (all of them, I hope). Evolving technology means evolving threats. Mobile malware has exploded this year, and every company with an online presence needs to fight against hackers and other network hazards.

“Security is a mainstream issue – especially with the explosion of mobile, cloud, and virtual computing,” said CEO Ron Gula. “Serious network attacks are far more common than anyone wants to publicly admit.”

These products are used by 15,000 organizations worldwide, including the U.S. Department of Defense and 12 out of 14 federal civilian departments.

The rest of the client list reads like a Who’s Who of American industry, including large corporations and businesses of every persuasion. Customers include technology leaders Dell, Google, Intel, Microsoft, Skype, Apple, and Yahoo; financial services companies Barclays, Deloitte, and Visa; universities including Brown, Michigan, and Ohio State; healthcare organizations such as Johnson & Johnson, Merck, and Coventry; energy corporations Chevron, and ConocoPhillips; media conglomerates CBS, Comcast, Time Warners, and 20th Century Fox; telecom providers Verizon and British Telecom; and retailers ranging from Chipotle to Zappos. To name a few.

Revenue has grown by more than 5 times over the past four years. In the past year alone, the company has had to double its staff and expects to double it again to accommodate high demand for is products.

It was founded in 2002, but only now took institutional investment in order to continue researching evolving and increasingly dangerous cyber threats, translate this research into product development, and accelerate global growth. The investment came from Accel Partners.

It is headquartered in Columbia, Maryland, with offices around the U.S. and the U.K. Read the full press release.