Amazon and Apple network servers may have been compromised by Chinese spy microchips, a Bloomberg Businessweek report claims.

What happened: U.S. investigators found that microchips were installed in servers used by various companies while they were being manufactured in China. The goal, per Bloomberg, was "long-term access to high-value corporate secrets and sensitive government networks."

The details: The discovery kicked off a government investigation which, after three years, is still going. No consumer data is believed to be compromised from the almost 30 companies that were affected.

• Supermicro, the U.S.-based company that assembles the affected servers, dominates the industry. While it assembles its products in the U.S., its core product, the motherboards, are manufactured in China. A former U.S. intelligence official told Bloomberg that attacking Supermicro "is like attacking Windows. It's like attacking the whole world."

The other side: Amazon, Apple, and Supermicro all disputed the findings of Bloomberg's report.

• Read the responses that each company provided to Bloomberg.
• Amazon said in a release on Thursday: "At no time, past or present, have we ever found any issues relating to modified hardware or malicious chips in SuperMicro motherboards in any Elemental or Amazon systems. ... There are so many inaccuracies in ‎this article as it relates to Amazon that they’re hard to count."