IcedID malware, in the hijacked email thread, with the insecure Exchange servers

Cyber-criminals are using compromised Microsoft Exchange servers to spam out emails designed to infect people's PCs with IcedID. IcedID is bad news because if you're tricked into running it, it opens a backdoor allowing further malware, such as ransomware, to be injected into your system. Marks typically receive an encrypted . …

[Zippy´s Sausage Factory]

The techniques get more and more elaborate once you've got the nasty, but the way to avoid it remains the same: don't open attachments unless you're 100% sure you can trust them.

But will people ever learn? Probably not.

[jvf]

I never open attachments from unknown parties. If I do know them, I call them so see if they actually sent me anything and, if so, what is it? If it’s something they’re just passing along, I don’t open it.

[Disk0]

The remedy

of course, is not using any MS products