First thing that comes to mind is that no one would suspect an iron. People are gonna beat their heads over these intermittent spam issues for quite a while before any correlation pops up. Second, if you add a battery to the chipset, then you can charge while the person's ironing and out spam throughout the week. Irons are pretty high power devices, so no one's really going to notice an extra watt or so.

Heavy? A lot of room in the handle? Nope... I'm stumped too, because I can't imagine there would already be a transformer in there for easy 5 - 12v power.

Speculation:

1. Heavy, relative weight difference is negligible. 2. Has power 3. Easy to open up and work with 4. Plenty of extra space inside 5. Travels into a diverse selection of households 6. (most important) the person has a day job in an iron factory.

I also like the theory this is just a PR stunt for someone like a local iron retailer, or it was a local mod done to the irons after they arrived in Russia.

That may be part of the reason. Common household item with somewhat unpredictable usage sounds like a good way to mask the activity.

I'm thinking hotel rooms could be a target. Irons that are used frequently and in close proximity to people connected to (or sharing) wireless connections.

Yup, all you need is a brief window to dump the malware on another box. Finding a malicious device is much harder if it's intermittent.