Don't get caught by fake emails, scam phone calls.
Never open convinsing emails pretending to be from your bank, online store, etc. They may try to install malware or trojan on to your computer, or take you to a fake website, to obtain your personal info. eg. username and password, bank account info.
Same applies to phone calls from scammers pretending to be from microsoft, google or some other company saying you have something bad on you computer and needs immediate attention. They then want to acquire remote control, install malware, trojans, run ransom software, or ask you to perform steps in order for them to gain access.
If you haven't asked someone to call you, then it's a fake,scammer caller.