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I work for this telemarketing company, and when I went to work this morning all my fax machines' outputs were jammed with black paper with the faded words "fuck you" transcribed on each of them.

I looked it up and it says its an electronic attack called a 'Black Fax', what should I do?

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I think every infromation you need is here – Kiwy Jan 7 '14 at 10:24
Two possibilities (1) just deserts - your company pollutes my phone, I pollute your faxes. (2) your attacker is a telemarketer hoping to sell toner cartridge refills. – ddyer Jan 9 '14 at 20:04
What's your fax number? I'll have 4chan figure it out for you... ;) – AJ Henderson Jan 10 '14 at 0:10
I think it shocks most people when they realize facsimile is insecure. – rook Nov 26 '14 at 16:34
what should I do? replace your toner cartridge. ;) – user42178 Nov 27 '14 at 3:23

By law, faxes have to have the sender's phone number printed across the top. This is by law, not technical requirement, which means it's quite possible to not have that information, or at least not have it correct. Either way, you should have call records available from your phone company to help track the perpetrator.

Armed with that information, go file a police report (and assuming USA, an abuse report with the FCC), and then wait for the dream of justice that may or may not ever come.

You may also want to consider an electronic-only fax option. All-black TIFF files cost a lot less to produce, so the effect of such an attack is minimal. You could roll your own using the appropriate software and a fax modem, or you could subscribe to a commercial offering.

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By law... - surely that's a jurisdiction specific thing? – symcbean Jan 7 '14 at 9:51
@symcbean laws always are. But this law (or some variant on it) is common in many countries. – tylerl Jan 7 '14 at 15:31
Given ubiquitous caller id spoofing, the number printed across the top, if any, is legally meaningless. Ask the NSA who called you. – ddyer Jan 9 '14 at 20:01
which jurisdiction? "Many" is not "all". – Ben Jan 9 '14 at 23:42

I have been tempted to do this before - people used to send us far too many unsolicited faxes and is annoying as hell.

The smart way to deal with this is how we deal with scum the sort of unsolicited faxes that get sent to us - Don't print them. Get a fax-modem on a PC, and recieve the faxes to them. Print what you need, trash the rest. In this case the cost of a black fax is essentially nothing, unless they do, effectively, a 1980s DOS and keep your fax machine tied up.

Practically though? Do as you want others to do to you. Ask politely. See if they prefer other channels or not at all. Make sure you have a clear functional opt-in/out policy. You and your kind have made this person mad (and a hero to many I suspect). Solve the root problem, not the symptom.

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Hey man, don't throw 'scum' around, some people make a living off of telemarketing. – rook Nov 26 '14 at 16:42
I was talking about the faxes, not the telemarketers. Unsolicited faxes were a plague when I was running IT stuff at a small engineering firm. I'm nice to telemarketers. I just tell them I'm not interested, and I'll save them the time. However the social aspect is important here - the attacker is obviously motivated by anger, and its worth consider his angle. – Journeyman Geek Nov 26 '14 at 21:44

Printing every fax you receive is a vulnerability in your system. You need to take responsibility, and defend your business from this denial-of-service attack.

Consider using an Fax over IP(FoIP), or a fax gateway service. The cheapest fax-to-email online service would also resolve this issue, and these services are typically cheaper than maintaining a physical fax machine.

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