Cell phones don’t always delete
SMSes, pictures and videos
reliably. We show you the right
way to do it.
An individual has an intimate
relationship with his cell phone.
The device listens to your
confidential company information,
knows with whom you go out with
and knows all the news, which you
send to your friends. The SMSes
can certainly be deleted from the
cell phone with relative easily, but
that is a superficial fact. Most of
the devices delete sensitive data
from the memory half-heartedly;
you can retrieve it without any fuss
using the relevant tools.
CHIP took used cell phones and
smartphones to try and restore the
SMSes, pictures, contacts and
videos – and the results were
remarkable. Supposedly deleted
data can be retrieved in an easy
way. We show you what is the
nature of this data and how you
can secure your cell phone before
passing it over to friends or
colleagues or even sell it on the
Internet.
Deleting contact data and SMSes
Every cell phone has certain
amount of data that is specific to
its owner. If the cell phone is
subsequently passed on, then it
should be wiped clean of this
compromising data. After all, there
are certain personal details which
its owner does not want to reveal,
even to his family members. The
same logic applies to office
phones, which is at times shared
between colleagues. Whether it is
personal or official, no one wants
to pass on his sensitive data in
unknown hands. You can always
use the delete function of the cell
phone, but this option comes with
loopholes.
To identify what could still be
found in the cell phone memory
after the supposed deletion, we
used a spy tool for professionals
called the Paraben’s Device
Seizure, which is available on
www.paraben-forensics.com . The
application costs approximately Rs
2,980; the site also offers a trial
version for 30 days with the
complete version of the forensics
tool. And yes, Device Seizure is a
tough nut
to crack.
After installation, we plugged in
current cell phone models to the
computer and set the spy tool on
the devices. The program creates
an image of the cell phone memory
that can be subsequently used with
the integrated hex editor. We thus
came across deleted contact data
and SMSes in a few cell phones,
which the previous owner had
received and deleted.
While tool did not work on all the
devices, it is, however, constantly
being developed. Thus, the danger
of unauthorized persons retrieving
your deleted data is very plausible.
To avoid such a scenario, you
should ideally first delete the data
on the SIM card and then
overwrite it. This makes it very
difficult or rather impossible for
forensics programs to restore the
contacts or messages. For doing
so, you must use a SIM card
reader such as the SIM Card Stick.
You can use it to access the SIM
card, load the contact data and
messages stored on your computer
and edit the entries there. It is
much more comfortable and even
much faster in case of several
messages as opposed to editing
data using the cell phone menu.
In addition, the software deletes all
the existing contacts on your SIM
card and overwrites them. Once
done, the overwritten contact data
can no longer be read.
Deleting pictures and videos
Unusual photos, videos or voice
notes are much easier to trace on
your cell phone than SMSes. This is
because modern cell phones and
smartphones are come with
multimedia centers have the in-
built storage space and microSD
cards to store your pictures,
videos and music. If you connect
the cell phone to the PC, it
normally detects the card as a
standard data carrier, integrates it
as a drive and allows full access to
it via Windows Explorer — just like
in case of a USB stick or digital
camera.
Hence you can have complete
access to the additional memory
and retrieve the deleted snapshots
or vacation clips on your computer
using tools such as O&O UnErase
(approximately Rs 2,000, www.oo-
software.com ) or the free to use
PC Inspector File Recovery tool;
and that too without too much
effort or in-depth knowledge about
computers. If you delete data;
particularly from the memory,
using the deletion function in the
cell phone or through the
computer, by moving them to the
recycle bin, the data is deleted
superficially. You only sweep it
under the carpet. And that is
exactly where the above-mentioned
tools look for it; striking gold in
most cases.
Many cell phone users do not think
of deleting data off the memory
cards correctly was proved as a
fact when we visited Second
Handy, which specializes in sale of
second-hand cell phones. We
randomly rummaged through cell
phones and came across wedding
photos, vacation photos, a whole
lot of MP3s and voice notes —
exposing the privacy of the
previous owner. We could even
find out the taste of music—from
“Jason Mraz” to "Savage Garden" to
“Red Hot Chili Peppers”.
Clearing the memory
cards correctly
If you want to pass on your cell
phone or plan to sell it, you must
force delete all the contents.
Meaning you must delete all the
data such that it's irrecoverable.
The best way to do this is using the
Open-Source-Software Eraser
( www.eraser.heidi.le ) or the
professional tool O&O Safe Erase
(approximately Rs 1,900, www.oo-
software.com ). These applications
enable quick deletion by replacing
the binary code of the data values
by invalid values. This trick helps
you effectively secure your
microSD cards, USB sticks, digital
camera memory cards, external
storage devices and hard disk
drives. This is an effective and
clever solution since files, once
overwritten, cannot be retrieved
even by using the best of software.
A downside of this technique is
that it reduces the life of your
flash devices. Flash memories have
limited life which is measured by
the number of read and write
cycles. Excessive deletion
procedures with several runs
reduce the life of your data
storage. Hence, you should be
careful while using programs such
as Eraser. Also moving your files
from to the Recycle Bin is not
enough. This is because only two
bytes are modified in the partition
table during
the simple deletion process; other
values such as the file name still
exist. Data recovery tools check
the tables where the deleted files
are located and restores them.
It is possible to restore the
contents of formatted drives, albeit
it is much more complicated than
retrieving deleted documents. For
instance, to restore photos
successfully after formatting the
storage devices and memory cards,
a recovery tool such as
DiskRecovery by O&O software
must scan the actual data field,
which is a rather lengthy process.
However, the software finally
detects the file type with the help
of its built-in database of templates
of different file formats. It can
restore a JPEG file or a Word
document for instance with the
help of this information.
Overwriting data without using a
PC
It is not possible to delete the
contents of the phone memory
from the PC if you do not have a
suitable flash card reader or the
device does not get connected as a
universal mass storage device.
However, there is a simple trick
and it works fine for other plug-
and-play devices as well. To do so,
first reset the cell phone to factory
settings so that the phone memory
is reset. Next, point the cellphone
camera to a neutral surface, for
example a white wall, and start
capturing a video until the phone
memory is full. If the cell phone
does not have this function, fill the
memory by clicking photos. The
old pictures and videos are
overwritten and irrecoverable.
If you have cleaned up your cell
phone using these tips, you can sell
your phone or pass it on to
someone without worrying that
your data can be retrieved.
CELL PHONES AS VIRUS
CATAPULTS: INFECTED MEMORY
CARDS INFECT THE PC
You should ensure that your cell
phone is devoid of all your
personal data if you are selling
it. However, there are lurking
dangers even when buying
phone – especially in case of
second-hand phones. This is
because undeleted memory
cards can contain malware.
Moreover, you cannot be too
sure even while buying new
products. This is what happened
with an employee of Panda
Security; an alarm was set off
when he tried to connect his
new HTC Magic smartphone by
Vodafone to the computer:
malware was detected on the
cellphone's memory card. The
analysis showed that it was a
Mariposa client. In addition, the
memory also contained the
Conficker worm and a Trojan.
ORIGIN STILL UNCLEAR
Vodafone reacted to this and
sent replacement cards to 3,000
affected users as well as
suitable removal software;
however, the data that was
hacked by the malware is now in
the hands of the hacker. Hence,
always check the microSD card
in your cell phone for malware –
especially if you are buying a
second-hand device.
CELL PHONE VIRUSES ARE
SPREADING
AS KASPERSKY REPORTS,
EUROPEANS ARE RELATIVELY LESS
AFFECTED BY CELL PHONE
VIRUSES; THEY ARE MORE
WIDESPREAD IN ASIA. AMONG
OTHER THINGS, MALWARE
INDEPENDENTLY SENDS SMSES
TO PREMIUM NUMBERS AND
FORCES UP THE CELL PHONE
BILL. VIRUSES HAVE THE SAME
TASK ON CELL PHONES AS THAT
ON THE COMPUTER: HACKING
PASSWORDS, LOGIN DATA AND
CREDIT CARD NUMBERS. A
POSSIBLE SCENARIO IS THAT
CRIMINALS MANAGE TO SET UP
CELL PHONE BOTNETS. THE
MAGNITUDE COULD BE GREATER
THAN IN CASE OF THE KNOWN
PC BOTNETS. AFTER ALL, THERE
ARE CLEARLY MORE NUMBER OF
CELL PHONES IN THE MARKET
THAN COMPUTERS. FOR NOW,
THERE ARE NO MOBILE
BOTNETS, BUT ONLY INITIAL
SETUP ATTEMPTS. IN NOVEMBER
2009, A HARMLESS MALWARE
MANAGED TO ENTER
JAILBROKEN IPHONES, I.E.
HACKED VERSION OF THE APPLE
IPHONE. IT DID NOT CAUSE ANY
DAMAGE, BUT WAS A PROOF-OF-
CONCEPT FOR CELLPHONE
BOTNETS. THERE ARE MANY
DIFFERENT CELL PHONE
OPERATING SYSTEMS, WHICH
MAKES IT DIFFICULT TO SET UP
BOTNETS. HOWEVER, CELL
PHONE VIRUSES RUN EASILY ON
PYTHON AND JAVA. HACKERS ARE
ON THE LOOKOUT FOR
SMARTPHONES THAT RUN
SYMBIAN AND WINDOWS
MOBILE OS. ACCORDING TO
KAPERSKY, ONE CAN EXPECT
MALWARE IN ANDROID
CELLPHONES AS WELL. THIS IS
BECAUSE, UNLIKE IPHONE WITH
ITS APPLE STORE, THIS SECURITY
PROGRAM IS MISSING IN
ANDROID OS .
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