Thousands of office printers from large businesses around the world are churning out page after page of gibberish and wasting vast reams of paper.

For once it seems malware is to blame.

Dubbed "Trojan.Milicenso," it has been described by security researchers as a malware delivery vehicle "for hire" through its repeated use since it was first discovered in 2010, according to security firm Symantec.

The worst hit appear to be large companies in the U.S., India, northern Europe --- including the U.K. --- and South America.

Symantec said there were a number of ways the malware can find its way onto PCs, including opening a malware-laden email attachment, through a compromised website, or posing as fake video codecs.

Once the malware is opened, it redirects the user to pages to serve up adverts; a common way for malware writers to generate quick revenue.

But one of the apparent "side effects" of the malware affects printers.

The malware unpacks a file in a PCs printer queue, which Windows then turns into a print job. Because these files aren't readable to ordinary folk without special tools, it churns out incomprehensible gobbledegook, and doesn't stop until the printer runs out of paper, disconnected from the power supply, or is attacked by a peeved systems administrator with an axe.

It's like dragging a system file into a plain-text editor: most of the time you'll see garbage.

If your corporate printers are seemingly spewing out incomprehensible rubbish --- it's either an overworked intern who's fallen asleep at the keyboard --- or more likely a malware infection.

Image credit: Ricky Leong/Flickr.

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