To Clone or NOT to Clone?

To Clone or NOT to Clone?

The purpose of this article is to reiterate the issues surrounding the best practice model of the forensic examination/data harvesting of mobile telephones and the isolation of radio signals. It’s not the intention of the author to critique any persons/methods or vendors of products/services but merely to highlight the issues which are still apparent today considering such methods have been adopted for well over ten years in the field of mobile phone forensics and which in the opinion of the author are yet to be addressed to a satisfactory level.

Best practice advocates the need to isolate the target device from any communication signal in order to prevent changes in existing live/deleted recoverable data. Bearing this in mind the most common practice is to utilise U/SIM cloning tools and to replicate a working copy of the target U/SIM or in some cases creating a working U/SIM for those target devices where the original U/SIM is not available. The majority or most commonly adopted tools/applications for such a method will only permit the examiner to copy the minimal data required to allow successful boot which are the ICCID and IMSI in the main with the addition of other parameters such as the MNC. Although it may be regarded as best practice in the main it’s not without issue. From experience and review/re-examination of cold and live cases the same problems are encountered yet not addressed to a satisfactory level.

There are several vendors of such products and in the main they are adequate to a degree however some vendors of such products do not appear to continue with the product development cycle of such functions as one would expect. We see improvements and development with the core functions of mobile phone forensic applications and that is most welcomed however the basic fundamental process in this case cloning of the target U/SIM are left behind. Thus how is it possible to continue or improve upon a best practice model if the basic fundamental requirements are not addressed?

Examples where failings have been noted are listed below:

1. Misrepresentation of acquired/harvested data:
Quite often through examination it has been noted certain data types are not translated or presented in the correct format. For example contact names may be missing as they are contained within the ADN of the U/SIM card and due to the cloning system have not been transferred through which in turn is replicated to other data sets such as SMS and call list.

2. Inaccessible data
Situations have been encountered where data is not available via the GUI of the target device thus the possibility of missing or non-examination of data exists. An example of this was encountered whilst examining a BlackBerry Bold device where the BBM application was not available without the use of the original target U/SIM, the reason being that the application or some functions were tied to the SIM Application Toolkit.

The above examples are just the tip of the iceberg and in the opinion of the author there are certainly more issues encountered in the use of U/SIM cloning systems when examining mobile telephones and/or devices which utilise the use of U/SIM cards.

So how can we overcome such issues and improve upon the best practice model? One solution is total radio isolation and the use of the original target U/SIM i.e. faraday enclosures/rooms. Unfortunately this option is not a satisfactory way forward due to cost, health & safety issues, practicality and when dealing with volume work.

For a more practical and sustainable solution the author would suggest that the vendors of such products/services review their product development cycle, obtain and work with the necessary feedback from seasoned practitioners with a view to providing far more robust products/services which at best eliminate U/SIM cloning issues or which offers the examiner more flexibility as to the cloning parameters required or at least work towards providing bulletins of known issues and possible solutions for identified issues.

Author: Vinny Parmar
Digital Forensic Practitioner
Accredited MTEB Mobile Phone Trainer

Mobile Telephone Examination Procedure

Mobile Telephone Examination Procedure

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This discussion continues on the theme to highlight, over the last five years, the diminishing quality of the knowledge in mobile telephone evidence training and very poor understanding by those giving advice about or presenting mobile telephone forensic evidence and opinion.
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By way of further illustration about poor understanding which was given in an advice note regarding mobile telephone examination procedure, the advice given:
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(1) by removing the battery of certain make/model of mobile telephone can lose the date and time stamp and call history, but using a Shielding Room can prevent this because you won’t need to remove the battery.
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(1a) the party giving the advice above then went on to suggest they did not think, by and large, the above is a better methodology that should be adopted and went on to advocate that the method of producing a clone test SIM (Access Card) appeared to them to be more appropriate.
.
A shielding room is used to prevent radio signals entering a given space that the shielding is designed to protect, and also prevent the mobile telephone from registering to the mobile telephone network; [it] cannot though prevent loss of full call history and date and time stamp irrespective of whether the mobile telephone is in a shielded room or not. Removing the battery on some older models of mobile telephone can lose the full call history and date and time stamp. To produce a clone test SIM (Access Card) the examiner is required at first instance to remove the battery to get to the SIM/USIM. So how is their recommendation shown (in 1a) that it is any better than the unsuitable Shielding Room scenario (in 1)?
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- For the record the point I am making is not to advocate shielding rooms or faraday bags, I am just pointing out the absurdity of the advice -
.
By noting in their advice that using a Shielding Room may not be the best method (thus tacitly negativing its use) the advice then goes on to positively suggest that the examiner wouldn’t need to remove the battery because it is in a shielding room and that call history and date and time stamp on the mobile telephone would be secure. They then go on to advocate the removal of the battery which implicitly requires taking the SIM out also from the handset for the purposes of producing a clone test SIM (Access Card). Their advice is confusing as they have already admitted removing the battery can lose data.
.
An examiner will naturally have to remove the SIM/USIM out of the handset anyway (thus removing the battery first is one point; another point being removing the SIM/USIM can inevitably cause loss of data in the handset - it can't be helped) because the proper order of examination requires a full examination of the SIM/USIM to get at evidence that is not readily available and obtainable by leaving the SIM/USIM in the handset during examination.
.
I concluded from reading their advice that it contained so many mixed messages and conflicting use of methodologies which each method that would usually be used for the treatment of different issues in isolation were now being squeezed together to make them work, would leave an examiner following their advice open to and vulnerable to potentially discrediting their own evidence.
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Moreover, if the advice note was intended to succeed in getting an examiner to use Access Cards over Shielding Rooms then in my view it failed to convince me to use one or not the other.

Mobile Telephone Examination Procedure

Mobile Telephone Examination Procedure

.
This discussion continues on the theme to highlight, over the last five years, the diminishing quality of the knowledge in mobile telephone evidence training and very poor understanding by those giving advice about or presenting mobile telephone forensic evidence and opinion.
.
By way of further illustration about poor understanding which was given in an advice note regarding mobile telephone examination procedure, the advice given:
.
(1) by removing the battery of certain make/model of mobile telephone can lose the date and time stamp and call history, but using a Shielding Room can prevent this because you won’t need to remove the battery.
.
(1a) the party giving the advice above then went on to suggest they did not think, by and large, the above is a better methodology that should be adopted and went on to advocate that the method of producing a clone test SIM (Access Card) appeared to them to be more appropriate.
.
A shielding room is used to prevent radio signals entering a given space that the shielding is designed to protect, and also prevent the mobile telephone from registering to the mobile telephone network; [it] cannot though prevent loss of full call history and date and time stamp irrespective of whether the mobile telephone is in a shielded room or not. Removing the battery on some older models of mobile telephone can lose the full call history and date and time stamp. To produce a clone test SIM (Access Card) the examiner is required at first instance to remove the battery to get to the SIM/USIM. So how is their recommendation shown (in 1a) that it is any better than the unsuitable Shielding Room scenario (in 1)?
.
- For the record the point I am making is not to advocate shielding rooms or faraday bags, I am just pointing out the absurdity of the advice -
.
By noting in their advice that using a Shielding Room may not be the best method (thus tacitly negativing its use) the advice then goes on to positively suggest that the examiner wouldn’t need to remove the battery because it is in a shielding room and that call history and date and time stamp on the mobile telephone would be secure. They then go on to advocate the removal of the battery which implicitly requires taking the SIM out also from the handset for the purposes of producing a clone test SIM (Access Card). Their advice is confusing as they have already admitted removing the battery can lose data.
.
An examiner will naturally have to remove the SIM/USIM out of the handset anyway (thus removing the battery first is one point; another point being removing the SIM/USIM can inevitably cause loss of data in the handset - it can't be helped) because the proper order of examination requires a full examination of the SIM/USIM to get at evidence that is not readily available and obtainable by leaving the SIM/USIM in the handset during examination.
.
I concluded from reading their advice that it contained so many mixed messages and conflicting use of methodologies which each method that would usually be used for the treatment of different issues in isolation were now being squeezed together to make them work, would leave an examiner following their advice open to and vulnerable to potentially discrediting their own evidence.
.
Moreover, if the advice note was intended to succeed in getting an examiner to use Access Cards over Shielding Rooms then in my view it failed to convince me to use one or not the other.