The redirection of both Lenovo's website and Google's main search page for Vietnam this week highlights weaknesses with the Internet's addressing system.
On Wednesday, visitors to lenovo.com were greeted with what appeared to be webcam images of a bored young man sitting in a bedroom, and the song "Breaking Free" from an old Disney movie. On Monday, Google's site for Vietnam also briefly redirected people to another website.
Both Google and Lenovo were victims of "domain hijacking," a type of attack against the Domain Name System (DNS), which translates domain names into IP addresses that can be called into a browser.
The domain name records for both companies were modified to redirect to different websites when people entered "lenovo.com" and "google.com.vn."
The changes were apparently made through Web Commerce Communications, known as Webnic.cc, a Malaysian company that registers domains names.
The hacker group Lizard Squad has claimed credit for the defacements. Lenovo appeared to restore service at one point on Wednesday afternoon, but later was unavailable due to system maintenance, a notice said. Webnic.cc could not be immediately reached for comment.
In Lenovo's case, the hackers changed Lenovo's domain name registration details to redirect to nameservers at CloudFlare, a San Francisco-based company that specializes in bettering the performance of websites through extensive caching. Nameservers tell a computer which IP address to look up to view a website.
CloudFlare's servers then redirected people trying to go to lenovo.com to two IP addresses hosted in the Netherlands by the company Digital Ocean, said Andrew Hay, senior security research lead for OpenDNS, a company that specializes in DNS-related security.
Those redirected to the other sites saw the webcam images of the bored young man. The source code for the Web page included the line: "The new and improved rebranded Lenovo website featuring Ryan King and Rory Andrew Godfrey," referring to persons who have reportedly been connected to the hacker group Lizard Squad.
The Lizard Squad's access to Lenovo's registrant account also allowed it to capture some of Lenovo's email, which the group posted excerpts of on Twitter.
Lenovo has already been under pressure in the last week for pre-installing a secretive application called Superfish on its laptops, which substitutes some ads on encrypted websites but also created a major security vulnerability.
CloudFlare offers free services that are sometimes abused by miscreants, but the company said it moved fast to help fix Lenovo's problem.
"As soon as we saw the unauthorized transfer, we took control of the account, notified Lenovo and worked with them to restore service while they worked on getting their domain back," said Marc Rogers, principal security researcher at CloudFlare.
Sign up for CIO Asia eNewsletters.