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.

Security on mobile Internet devices is more serious than traditional cyberthreats, said Du Yuejin, the center's deputy chief technology officer. Hackers are increasingly exploiting downloaded software on smartphones through app stores, Du said.

"User information on smartphones is the target of hackers," Du said. "Meanwhile, a mobile device can stay online for quite a long time, which provides the time attackers need to get what they want."

Security threats come mostly from malware, but malware is difficult to detect when people download apps, he said.

The center screened about 2 million mobile software programs sold in various Chinese app stores.

Around 800,000 programs had a total of more than 7,000 malware programs, which have been downloaded more than 100 million times.

Malware surfs the Internet and sends messages without the users' knowledge after stealing data, Du said.

"Mobile users should enhance their awareness of the problem, but it's more important to urge our security companies to take precautionary measures," he said.

Zhang Zhenghua, chief adviser of cloud ecology system with Baidu, a major online search engine, agreed, saying his company has invested 100 million yuan ($16.3 million) on improving cybersecurity.

So far, the company has identified 60 million fake websites and kicked 170,000 unqualified users off line, Zhang said.

"We have also cooperated with the authorities, including Beijing Public Security Bureau, to improve our verification system and avoid phishing websites," he added.