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- "An Interesting Diversion"
-
- By Lord Phreaker
-
- From: 2600 magazine, October 1985
-
-
- -------------------------------------------------------------------------------
- A diverter is a form of call forwarding. The phone phreak calls the customers
- office phone number after hours, and the call is "diverted" to the customers
- home. This sort of service is set up so the phone subscriber does not miss
- any important calls. But why would a phreak be interested? Well, often
- diverters leave a few seconds of the customers own dial tone as the customer
- hangs up. The intrepid phreak can use this brief window to dial out on the
- called party's dial tone, and, unfortunately, it will appear on the diverter
- subscriber's bill.
-
- HOW DIVERTERS ARE USED
-
- One merely calls the customer's office number after hours and waits for him
- to answer. Then he either apologizes for "dialing a wrong number" or merely
- remains silent so as to have the customer think it's merely a crank phone
- call. When the customer hangs up, he just waits for the few seconds of dial
- tone and then dials away. This would not be used as a primary means of
- calling as it is illegal and multiple wrong numbers can lead to suspicion,
- plus this method only works at night or after office hours. Diverters are
- mainly used for calls that cannot be made from extenders, International
- calling, or the calling of Alliance Teleconferencing (see 2600, May 1985) are
- common possibilities. Another thing to remember is that tracing results in
- the customer's phone number, so one can call up TRW or that DOD NORAD
- computer with less concern about being traced.
-
- Some technical problems arise when using diverters, so a word of warning is
- in order. Many alternate long distance services hang up when the called
- party hangs up, leaving one without a dial tone or even back at the extender's
- dial tone. This really depends on how the extender interfaces with the local
- phone network when it comes out of the long haul lines. MCI and ITT are known
- to do this frequently, but not all the time. Also, hanging on the line until
- "dial window" occurs doesn't work every time.
-
- Now the really paranoid phreaks wonder, "How am I sure that this is ending
- up on someone else's bill and not mine?" Well, no method is 100% sure, but
- one should try to recognize how a full disconnect sounds on the long distance
- service of his choice. The customer's hanging up will generate only one click,
- because most diversions are local, or relatively local as compared with long
- distance. Also, the customer hanging up won't result in winks - little beeps
- of 2600 hertz tones heard when an in-band trunk is hung up. The 2600 hertz
- tone returns to indicate the line is free, and the beginning burst of it is
- heard as it blows you off the line. Also, if there are different types of
- switching involved, the dial tone will sound radically different, especially
- between an ESS and a crossbar or step-by-step, as well as sounding "farther
- away". These techniques are good for undrstanding how phone systems work and
- will be useful for further exploration. The really paranoid should, at first,
- try to dial the local ANI (automatic number ifentifier) for the called area
- and listen to the number it reads off. Or one merely cals the operator and
- says, "This is repair service. Could you tell me what pair I am coming in on?"
- If she reads off the phreak's own number, he must try again.
-
- HOW TO FIND DIVERTERS
-
- And now a phreak must wonder, "How are these beasties found?" The best place
- to start is the local yellow pages. If one looks up the office numbers for
- psychiatrists, doctors, real estate agents, plumbers, dentists, or any
- professional who generally needs to be in constant contact with his customers
- or would be afraid of losin gbusiness while at home. Then one merely dials up
- all these numbers after 6:00 or so, and listens for multiple clicks while the
- call goes through. Since the call is local, multiple clicks should not be the
- norm. Then the phreak merely follows through with the procedure above, and
- waits for the window of vulnerability.
-
- OTHER FORMS OF DIVERTERS
-
- There are several other forms of diverters. Phreaks have known for years of
- recordings that leave a dial tone after "ending." One eof the more famous was
- the DoD Fraud Hotline's after hours recording, which finally ended, after
- multiple clicks and disconnects, at an Autovon dial tone. One common practice
- occurs when a company finds its PBX being heavily abused after hours. It puts
- in a recording saying that the company cannot be reached now. However, it
- often happens that after multiple disconnects one ends up with a dial tone
- inside the PBX, thus a code is not needed. Also, when dialing a company and
- talking (social engineering) with employees, one merely waits for them to hang
- up and often a second dial tone is revealed. 976 (dial-it) numbers have been
- known to do this as well. Answering services also suffer from this lack of
- security. A good phreak should learn never to hang up on a called party. He
- can never be sure what he is missing. The best phreaks are always the last to
- hang up the phone, and they will often wait on the line a few minutes until
- they are sure it's all over. One item of clarification - the recordings
- mentioned above are not the telco standard "The number you have dialed..." or
- the like. However, telco newslines have been known to suffer from diverter
- mis-disconnect.
-
- DANGERS OF DIVERTING
-
- So, nothing comes free. What are the dangers of diverting? Well, technically,
- one is committing toll fraud. However, a list of diverter numbers is just
- that, a list of phone numbers. Tracing is a distinct possibility but the
- average diverter victim does not have the technical knowledge to identify
- the problem.
-
- There has been at least one investigation of diverter fraud involving the FBI.
- However there were no arrests and the case was dropped. It seems that one
- prospective victim in Connecticut realized that he was being defrauded after
- receiving multiple phone calls demanding that he put up his diverter NOW so
- that a conference call could be made. He then complained to the FBI.
- However, these aware customers are few and far between, and if a phreak does
- not go to such radically obnoxious extremes, it is hard to be caught. Unless
- the same number is used to place many expensive calls.
-
-