There was one security issue about Lenovo's computers.
Part of Lenovo's products, be sold during Sep. 2014 and Jan. 2015, are pre-installed one software called "superfish" on Windows platform. Some users found that it is spying the users' search activities and inserted some ads in the Google search results, no matter what browsers they used.
That means this software is collecting your search behavior, storing the data into its' remote server. Moreover, it might monitor your online transactions because this malware ran in operating system layer, binding into the browsers (including Internet Explorer and Chrome) , not as a browser extensions.
The production models may be affected are listed below:
G series: G410, G510, G710, G40-70, G50-70, G40-30, G50-30, G40-45, G50-45
U series: U330P, U430P, U330Touch, U430Touch, U530Touch
Y series: Y430P, Y40-70, Y50-70
Z series: Z40-75, Z50-75, Z40-70, Z50-70
S series: S310, S410, S40-70, S415, S415 Touch, S20-30, S20-30 Touch
Flex series: Flex2 14D, Flex2 15D, Flex2 14, Flex2 15, Flex2 14(BTM), Flex2 15(BTM), Flex 10
Miix series: MIIX2-8, MIIX2-10, MIIX2-11
Yoga series: Yoga 2 Pro-13, Yoga 2-13, Yoga 2-11BTM, Yoga 2-11HSW
E series: E10-30.
You can visit the following link to know how to remove the malware.
1. Mike Shaver. (2015, Feb. 15) Lenovo caught installing adware on new computers [Online]. Available: http://thenextweb.com/insider/2015/02/19/lenovo-caught-installing-adware-new-computers/
2. Dave Neal. (2015, Feb. 20) Lenovo: Superfish is gone and was never on ThinkPads or business desktops [Online]. Available: http://www.theinquirer.net/inquirer/news/2396033/lenovo-caught-shipping-pcs-with-pre-installed-superfish-malware