Baidu's (NASDAQ:BIDU) push into security software -- a move that seemed born more out of revenge than strategic opportunity -- is starting to pay off. China's leading online search engine revealed yesterday that Baidu Antivirus was named this year's "most promising antivirus" in's Big Antivirus Comparison. 

Baidu Antivirus placed third overall in system performance, and that's a pretty notable achievement for the rookie.

Baidu has always been more than just a search engine, but its entry into the antivirus software gained steam shortly after Qihoo 360 (NYSE:QIHU.DL) introduced its own search engine two summers ago. Qihoo 360 was best known for its Chinese market leadership in Web browsers and security software solutions, but its decision to enter into Baidu's lucrative turf didn't sit well with investors -- or Baidu.

Qihoo 360's goal has been to direct the growing audience for its browser and virus protection program to its search portal, and now it seems as if Baidu is trying to shake up the market as a way to either secure search visitors itself or to siphon off some of Qihoo 360's market share.

An important point here is that Baidu isn't limiting its security play to China. Baidu Antivirus can be used on all tablets and PCs running Windows, and it's currently available in English, Thai, and Portuguese. The program is a completely free download. 

Search has been more than enough for Baidu, just as security software and Internet browsers have been more than enough for Qihoo 360. 

Analysts see revenue at Qihoo doubling this year and soaring 58% come 2014. Baidu isn't growing as quickly. Wall Street's targeting top-line growth of 41% this year and 37% next year. However, the point is that both companies have been able to expand their businesses even as a rival invades its turf. 

Baidu is throwing its hats into many different rings these days. It has made deals this year to expand its role in mobile apps, e-commerce, and video. These moves have pressured margins in the near term, but the market's patient. It knows that Baidu's covering so much ground in cyberspace to make sure that it's never too far away when somebody wants to launch a search query. 

Keeping computers safe so that they can continue to surf freely is just a welcome byproduct of this venture.