Trojan.Milicenso is a Trojan that sends printers crazy, making them print pages of garbled nonsense until all the paper has been used up. The worst hit regions were the US and India followed by regions in South America and Europe, including the UK. The Trojan is actually a backdoor that is used to deliver other malware on the affected machines. The infection vectors are links and malicious attachments in unsolicited emails, as well as websites hosting malicious scripts that trigger the download of the Trojan. It redirects the user to pages to serve up adverts.
Source: https://thehackernews.com/2012/06/trojanmilicenso-print-bomb-printer.html