On the other hand, though, can a Mac get commandeered in the manner described?
The idea of botnet is new to me too, but I learned a bit more
at this site. I've poked around a bit, and I can't find any reference to a botnet or any other type of malware that uses Macs to send spam emails….
On further checking, neither have I and I'm assuming that the lessened (or no) likelihood of Macs involved in this kind of spamming is the reason behind these points in the MacManiac notes to deniro:
Do you have any Windows computers on your home network?
I'm still discounting your primary computer as not being a primary suspect in this issue.
I would discount the iPad and the printer as possible culprits.....my strongest suspicion would rest on the Windows 8.1 Dell as the most likely component.
However, I'm certainly finding this an informative thread and, even if the Mac itself may not be be the villain, I thought this was interesting:
The one outside factor that might actually produce the spams supposedly originating from your assigned IP address might be some other "smart" device installed on your home network.....such as a NAS or even another networking device such as a WiFi extender or second access point....these additional network components are normally controlled by an embedded processor running some variant of Linux and potentially they can be and might have been hacked in the past.
