It is a good idea to keep your computer systems up-to-date, by installing the latest software fixes. But there is one fix that Telstra needs to request and install, to fix a bug lurking on Telstra’s landline telephone system which scammers are making use of.
This is Part 4 of 4 of Scammers making use of Telstra landline bug.
- To learn about the scam, read Part 1
- to learn more about testing your landline and protecting yourself, read Part 2
- To find out how I became an unwitting victim 21 years ago, read Part 3.
Here, we explore some myths and facts about this bug, and I have some requests for information (please comment if you can answer any of the questions).
Facts and myths
- Fact:
- Scammers can intercept calls you make (shortly after they call you)
- Myth:
They’re intercepting all calls that everyone is making to 000, or the bank
The truth: there’s been a few crimes like this in the past (against radio stations), but not this time. Only one person’s calls get intercepted.- Fact:
- An evil caller can control your landline, preventing you from making calls, for up to five minutes.
- Myth:
Scammers can make calls to sex lines in Nigeria from your line
The truth: They cannot; if you see such calls on your bill, it was probably a family member or employee.- Fact:
- Scammers can imitate the bank’s phone menu (or they could make a temporary, actual connection which they cut off at the right time)
- Myth:
This bug enables them to fake my Caller ID
The truth: A separate hack applies to Caller ID, which the scammer might also use as part of their fraud.- Fact:
- An evil caller can prevent other callers from getting through to you (they get busy tone).
- Myth:
They can listen in on everyone who calls you
The truth: They have to physically wire a listening device across your line to do that. The method described here only allows a scammer to intercept calls you make, shortly after their call.- Fact:
- There is no indication if a call is still connected on the line after you hang up.
- Myth:
A scammer can be secretly connected to your line at any time
The truth: It doesn’t “just happen”. They have to call you first, and the effect only lasts for five minutes (maximum, in Australia).- Fact:
- Mechanical exchanges also had this characteristic
- Myth:
Every country operates like this
The truth: Only a few countries have this bug. New Zealand, Canada, the U.S., and many other countries do not have this bug. And mobile phone systems do not have this bug, either.- Fact:
- Various scams and tricks arising from this bug have been in use for some time. In the past, there was no five-minute timer, so it was possible to lock out someone’s line for weeks. Journalists and reporters, having interviewed someone for a story, would leave the call open preventing competeting journalists from calling their victim and getting the same story.
- Myth:
Surely the Police would speak to Telstra about this?
The (horrible) truth: I’m not convinced it’s even occurred to them that it’s a bug, nor am I convinced that they’ve actually spoken to Telstra about it. But I am sending information to the Police about this, firstly to ascertain what has transpired, and secondly, (from a crime prevention perspective) to persuade them to be more on the front foot with Telstra on this issue.
The only sign of action by the authorities I can find is the British Financial Ombudsman Service has called for action by (British) telecoms companies to remedy the flaw in hanging up phone lines.
![Map of Australia showing various towns.](http://www.geekrant.org/files/2007/Australia-map.png)
Land of the Long Held Call[1]
![Map of New Zealand showing various towns](http://www.geekrant.org/files/2007/New_Zealand_map.png)
Land of the Long White Cloud[2]
Where is the bug?
It is in the telephone exchanges – specifically, the software running inside the exchange. This has to be fixed, either by the manufacturer of the telephone exchanges (Ericsson), or by someone changing a configuration setting. Telstra has to request this in either case, and it is likely to take 3-6 months to fix.
The official term for this is CSH (Called Subscriber Held) or A-party Release. I call it a nasty bug, but unfortunately, it is hard to convince Telstra that this needs fixing.
I have some questions
While researching anything like this, it is natural for questions to arise. Does anyone have information on anything below, or anything else? Please leave a comment.
Note that comments usually require approval before appearing, which I generally check three times a day … agree or disagree, I approve “anything” on-topic.
- Australia: Does anybody using Optus Cable (or other HFC services) experience the problem? Please do the test to find out.
- New Zealand: Did CSH apply on Crossbar or Step-by-Step exchanges (say, before 1980)?
- New Zealand – TelstraClear subscribers: Can someone do a test, to see if CSH applies to Telstra’s exchanges in NZ?
You are probably a TelstraClear subscriber if your telephone number begins with 9xx xxxx, and if your TelstraClear bill shows a line item for Telephone Line Rental or Monthly Charges. - Britain: There was a proposal to reduce the CSH hold period to 10 seconds. Was this implemented?
- U.S.: I don’t want to believe the movies too much 🙂 but they frequently show the B-party hanging up and the A-party receiving dial tone. Is that true?
- All countries: Please do the test. It’s for your benefit to be aware of the situation, as well as our curiosity 🙂
If you have information, please fill out a comment (note: DELAY before it appears, for most people).
Footnotes
- [1] CIA World Factbook / Wikimedia Commons / Public Domain
- [2] CIA World Factbook / Wikimedia Commons / Public Domain