QQHelper is one of the most annoying trojans lurking online. QQ Helper is a downloader trojan. This means that it is capable of downloading and installing other malwares. QQHelper doesn’t hide its presence on the compromised machine: it appears as a toolbar on web browser. This trojan is installed by other trojans, but it may also come as part of other malware. QQHelper may also infect computer when user visits a malicious website. This trojan is always installed without user’s permission. The toolbar installed by trojan is possibly fraudulent online search toolbar dedicated to Korean people. But the toolbar is not the main function of QQHelper. It also downloads and run other malwares. Those may lead into loss of private information and money.

Source: http://www.2-viruses.com/remove-qqhelper