It started with a string of symbols, ominously popping out of a random printer.
Then another...
...and another...
...and another, all within the space of an hour.
Some of the characters seemed to point to SQL injection, a kind of malware. Most printers have little to no security, so it would be easy for hackers to slip in. But then why print random characters?
The only thing the printers had in common was a certain networking setup.
Also, the printers wouldn't go into sleep mode, which seemed like a bad sign.
The best guess, made by a Hacker News commenter, didn't really suggest malicious activity. He proposed that a loose port scanner had stumbled onto the printer's JetDirect port, and the mysterious string of characters was just the scanner's automatic network query. A security flaw, for sure, but nothing to call the feds about.
But be careful when you're loading toner, just in case.