Qihoo 360 Technology Co (Qihoo 360) denied on Monday cheating in evaluation tests conducted by security testing body AV-Comparatives (AV-C) and attributed the dispute to AV-C's protection of its own commercial interests.

Chinese security vendor Qihoo 360 said at a press conference held in Beijing on Monday that the test version of their antivirus products it had submitted to AV-C is the same as what it offers users, except for a different setting in the default engine.

The company also said in a Monday press release that China should have its own security products evaluation system and testing bodies.

The press conference was held one day after Qihoo 360 announced it would withdraw from tests conducted by three international security testing bodies which said Thursday that they will revoke all certifications and rankings awarded to Qihoo 360 this year.

The three institutions said the company submitted products for testing that had an anti-malware engine provided by Romania-based Bitdefender, which is disabled in Qihoo 360's main market regions including China.

Yu Guangdong, vice president of Qihoo 360, said at the conference that Qihoo 360's antivirus products have assembled several engines with the aim of adapting to different security threats in different countries and regions.

"Users can choose which engine they want to use. We submitted the antivirus products for tests with Bitdefender as the default engine while we give our Chinese users a product with QVM as the default engine," Yu said.

"[This is] because Bitdefender is developed by a Western firm and has an advantage in Western countries, but the QVM engine developed by Qihoo 360 is more effective in China," said Yu. 

Qi Xiangdong, president of Qihoo 360, said the key reason for the dispute with the three bodies - AV-C, AV-TEST and Virus Bulletin - is that Qihoo 360's overseas expansion plan has threatened the commercial interests of competitors and testing institutions.