German IT news website golem.de reported [1] about Microsoft customer who was trying to migrate on-premise Exchange server to Office 365. 26h after he placed his O365 order he received a link to a migration tool. The tool had been replaced by a 1kB text file saying:
> If Microsoft gave a damn about security, they would never have released their own binaries to customers. At least not after some product manager has decided to change the distribution location of the file, then delete their own blob storage account and thus make the file publicly available to everyone.
Turns out the migration tool (exe file) was write-accesible to anyone.
[1] Archived article - https://archive.is/EKTHv