https://www.recode.net/2017/10/9/16450320/microsoft-2016-presidential-election-russia-bing-investigation

Microsoft is currently reviewing its sales records to determine whether trolls aligned with the Russian government purchased ads on Bing or other company products during the 2016 U.S. presidential race.

The decision to conduct an internal investigation comes as Microsoft’s tech industry peers — Facebook, Google and Twitter — contend with parallel probes by the U.S. Congress into the extent to which Kremlin-backed agents spread disinformation on their platforms around Election Day.