Routine maintenance on one of the technology giant's data centers revealed unusual traffic from computers infected with a form of malicious software, according to Google security engineer Damian Menscher.

The traffic was sent to Google through intermediary computer servers referred to as "proxies," Menscher said.

Google began delivering warning notices along with search results to computers that appear infected with the virus.

"We hope that by taking steps to notify users whose traffic is coming through these proxies, we can help them update their antivirus software and remove the infections," Menscher said in a blog post.

"We hope to use the knowledge we've gathered to assist as many people as possible."