One time my Mom got a call from a random number(It was something unusual about the phone number, it was 7 digit). The person on the phone was pretending to be a MS employee and had an accent. What my mom told me. The guy said the they have been informed about a malware/virus which has effected her computer and need to resolve that issue. She is said fine. He gave her some instructions to flow. Asked to her open command prompt. Which my mom didnt even knew exists on a pc. He made her type some commands and later went asked her to look into system logs. Off course there were some failure logs in red. The guy told her that's because of virus. He wanted to her install teamviewer and give her the access details. My mom is not a tech savy person. All she knows, is to open google chrome and watch netflix. She said she need to call my son to find out more. The guy was getting impatient and hang up the phone.
Now, tech savvy people like me can detect spammers/scammers way before in this scenario. But for my mom it took a while. The guy said he was calling from Microsoft and even knew the some ID code of my computer, what she told me. She fell for that. Fortunately, her account doesnt have admin privileges.