The company is also growing internationally, with installations in 150 countries, and Tenable plans, in part, to use the new money to continue that expansions. The company's team says that one of its key advantages is the fact that it's not just doing a traditional security audit every week or month, but also passively monitoring the network, all the time. In mobile, for example, Tenable can't scan every device during an audit, because many of those devices are sleeping. But during the passive monitoring period, Tenable can still look at device traffic for "telltale signs" of vulnerabilities. "Mobile and virtual have really changed the way that IT shops are having to exist," says Tenable President and COO Jack Huffard. "We felt to in order to really make this a big, standalone company, we needed to get into those markets fast, and we needed a partner that can help us do that." Oh, and here's a fun video visualizing an office network that Tenable shared earlier this year.