ForeScout Technologies, a firm that makes a security platform combining clientless network access control (NAC) and intrusion prevention, has raised $8 million from previous investors.

ForeScout’s CounterACT appliance works without software installation by individual devices on a network, thus attempting to remain invisible to users.

NAC has been gaining favor in corporate IT departments, and ForeScout has been on top of the wave; according to the company, it grew 80 percent last year.

The funding was provided to the Cupertino, Calif.-based company by Accel Partners, Amadeus Capital Partners, Meritech Capital Partners and Pitango Ventures. ForeScouts previous round, its fourth, was for $11.25 million, and also included only returning backers.