The company claims it has 450 million users worldwide, with over 80 percent of the Chinese Windows security software market for starters, but the name is still not well known in the UK. AVG and Avast has the majority of the free ‘sales’ of AV software here. See all CD/DVD autoring reviews. The initial impression of 360 IS is clean and modern. Though it doesn’t sport the feature set of some of the other products reviewed here, it does have one thing none of the others claim: it uses three different AV engines. These comprise Qihoo’s own ‘checksum-based’ engine in the cloud; a machine learning QVM engine; and, perhaps the biggest surprise, a BitDefender local engine. Working the three together is no mean feat and little icons in the control panel show the status of each engine separately. As well as AV protection, the program offers support against malware by checking for suspicious use of PC resources and web protection by using a database of known troublesome websites and issuing anti-phishing alerts. There’s a sandbox, too, where you can load untested programs to check they’re no threat and a trace cleaner, which removes browsing history and unwanted media remnants. Qihoo could be particularly useful on laptops, as it claims to prevent unauthorised webcam access. While this might be more of a problem in mainland China than here, recent revelations about the NSA and GCHQ’s scope of operation with the general public suggest we should be more concerned about unwanted images of us being captured. What it doesn’t have is specific modules aimed at spam or providing parental control, and there’s no firewall, backup or PC tune-up offering. This software is pretty much an AV product, despite its IS label. Our 50GB scan test completed in just under 39 minutes and examined 68,146 files. This gave a scan rate of 29.2 files/sec, at the lower end of the performance scale, but still acceptable. A repeat scan finished in 31 minutes, while testing exactly the same number of files. We’re not sure where it made up the eight minutes. The 1GB copy test took 45 sec without a scan running and 55 sec with one, showing a resource hit of just 22 percent in this particular task. That was with the 360 IS scanner set to the default fastest scan, not the setting for least performance hit. AV-Test rated the Qihoo engine a full point above both AV and Avast, at 15.5/18.0. This is a very good score for a free AV product. It breaks down to 5.0/6.0 for Protection, 4.5/6.0 for Performance and a perfect 6.0/6.0 for Usability.