https://www.bleepingcomputer.com/news/security/microsoft-discovers-supply-chain-attack-at-unnamed-maker-of-pdf-software/

Microsoft said today that hackers compromised a font package installed by a PDF editor app and used it to deploy a cryptocurrency miner on users' computers.

The OS maker discovered the incident after its staff received alerts via the Windows Defender ATP, the commercial version of the Windows Defender antivirus.