A recently unleashed piece of malware is wreaking havoc in some enterprises by causing all their printers to print gibberish until they run out of paper, researchers from Symantec said.

"The impact is global and effecting approximately 80 print servers," an admin of one Fortune 500 company wrote in an online forum dedicated to the print bomb explosion. "The print job names were all 15 characters in length and unique. The print jobs were all garbage print, as if it was opening the .exe and printing the garbage text." Other participants reported the same phenomenon caused hundreds of their organizations' printers to run through reams of paper.

According to a blog post published Thursday by researchers from antivirus provider Symantec, the nuisance is being spread by Trojan.Milicenso. The worst hit regions are the US, India, Europe, and South America. Milicenso is a fairly sophisticated backdoor that serves as a for-hire delivery vehicle for other pieces of malware. One of its malicious payloads, known as Adware.Eorezo, is dropping an executable file in printer spooler directories, causing some applications to print representations of the binary code.

"This explains the reports of unwanted printouts observed in some compromised environments," the Symantec post stated. "Based on what we have discovered so far, the garbled printouts appear to be a side effect of the infection vector rather than an intentional goal of the author."