Mobile devices have become a key target for hackers, as the amount of malicious software, or malware, on the devices has soared since last year, a new report says.

More than 160,000 malware samples on mobile Internet devices were found in 2012, about 25 times more than in 2011, according to security companies and the National Computer Network Emergency Response Technical Team and Coordination Center.

More than 80 percent of the malware targeted smartphones that use the Android operating system, and most was downloaded through smartphone application stores and forums, the center said.