A fridge has been discovered sending out spam after a web attack managed to compromise smart gadgets.
The fridge was one of more than 100,000 devices used to take part in the spam campaign.
Uncovered by security firm Proofpoint the attack compromised computers, home routers, media PCs and smart TV sets.
The attack is believed to be one of the first to exploit the lax security on devices that are part of the "internet of things".
The spam attack took place between 23 December 2013 and 6 January this year, said Proofpoint in a statement. In total, it said, about 750,000 messages were sent as part of the junk mail campaign. The emails were routed through the compromised gadgets.
About 25% of the messages seen by Proofpoint researchers did not pass through laptops, desktops or smartphones, it said.
Instead, the malware managed to get itself installed on other smart devices such as kitchen appliances, the home media systems on which people store copied DVDs and web-connected televisions.
Many of these gadgets have computer processors onboard and act as a self-contained web server to handle communication and other sophisticated functions.
Investigation by Proofpoint into the internet addresses involved in the attack revealed the presence of the smart gadgets, said David Knight, general manager of Proofpoint's information security division.
"The results spoke for themselves when the addresses responded with explicit identification, including well-known, often graphically branded interfaces, file structures, and content," he told the BBC.
Mr Knight speculated that the malware that allowed spam to be sent from these devices was able to install itself because many of the gadgets were poorly configured or used default passwords that left them exposed.
He said attacks such as this would become much more routine as homes and furnishings got smarter and were put online.
"Many of these devices are poorly protected at best and consumers have virtually no way to detect or fix infections when they do occur," he added.