Opened a Fake Invoice Attachment and Suspect Your PC Is Infected: First Cut the Network and Stop Payments, Then Determine Whether It's Remote Control

If you accidentally opened a "invoice" attachment and suspect your computer is infected, first disconnect from the network, stop all payment actions, change passwords on a clean device, and terminate sessions. Then, based on whether files are encrypted, distinguish between a remote access trojan and ransomware and follow the appropriate response path, determining when professional incident response is needed.