Thanks to the rapidly-growing smartphone market—and with it, the ever increasing risk of hacking—smartphone security startup Lookout has raised $11 million in a series B round of venture funding, the company announced Tuesday.

The cash infusion comes barely six months after San-Francisco-based Lookout pulled in $5.5 million from its Series A round in December. The company was founded in 2007.

Lookout supplies security services across all major platforms, ranging from software that protects from malware to locating or wiping missing phones. Its services are available on 400 mobile networks in 170 countries. In February, a Rutgers University team of researchers revealed that smartphones potentially are vulnerable to hijacking by software viruses that can turn them into eavesdropping or tracking devices -- or allow remote control activation of battery-draining applications.

Lookout's Series B round was led by Palo Alto venture capital giant Accel Partners. Other investors included Khosla Ventures (which led the company's Series A round) and Trilogy Partners.

"The smartphone market is exploding, and consumers are downloading third-party apps by the hundreds, making security an increasingly vital component of the mobile market," Ping Li of Accel Partners said in a statement. (He's joining the company's board.)  "Consumers need to know that their applications, their data, and their phone itself are protected. We are excited to work with Lookout as they continue to extend their lead in this dynamic market."

The smartphone market has grown more than 50 percent in the last year alone. In March,  Vodafone accidently distributed a virus to thousands of its HTC Magic phones.

"Here is yet another example of a company distributing malware to its userbase. Unfortunately it probably won't be the last," researcher Pedro Bustamente of Panda Security, a computer security firm, said in a blog post.

Lookout says it plans to use its funds to shore up its security infrastructure and invest in new technology.