That a modern smartphone with Internet access and a multitude of nice
features is liable of being hacked similar to a PC is evident. On the
other hand, a non-smart mobile phone, of design of the earlier
generation, unintelligent, clumsy, no Internet access, though yet
purchasable for telephone and SMS purposes only, could IMHO easily
mislead one to think that the device may be sufficiently secure against malicious manipulations. The fact, I presume, is however that, if an
adversary is capable enough to enter the cellular network, he could
access the SIM card to perform his malicious work. A recent personal
experience of mine is the following: I bought such a device and a
pre-paid SIM card, entered the telephone numbers of my friends into its
contact address list and informed my friends of my new mobile phone
number. Soon, though at a rather low frequency averaging roughly one
event per day, a number of my friends complained that I had called them
but strangely never attempted to say even a single word. It turned out
that the device each time seemingly arbitrarily selected an entry in
the contact address list and called automatically, which could also be
verified by its list of all outgoing calls. As remedy I deleted all
telephone numbers of my friends in it, leaving however for experimental
purpose my own home telephone number. One following night I had then
the uncommon experience of being awoken by a call from my own mobile
phone! (Actually two new mobile phones of the same brand were tested.
Following my complains of the said phenomenon, the vender gave me a
new exemplar in exchange, so that the probability of there being a manufacturing problem is vanishingly small.)

Another phenomenon that co-occurs with the above is that the device
powers off automatically at a frequency comparable to the first, even
though its battery is sufficiently loaded.

Being a layman in such issues, I should be very grateful for exact
explanations of the phenomena.

Remarks:

(1) I am mainly interested in technical explanations of the phenomena,
i.e. whether it is indeed true, and if yes how, that the SIM card in my
mobile phone got manipulated, and personally deem it neither favorable,
nor essential, realistic, etc. to conjecture on the motivations behind
such manipulations, if these indeed happened.

(2) Googling with e.g. "cell phones calling themselves" will turn up
a lot of apparently similar cases which, I guess, could stem from
diverse different causes in practice. It seems that there have not been
much scientifically exact and detailed investigations done on the issue
and that the phenomenon can occur both to modern smartphones with
Internet access (hence higher liability of being hacked) and to the
non-smart mobile phones without Internet access.

M. K. Shen

----------------------------------------
http://mok-kong-shen.de

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)