homepage
Open menu Go one level top
  • Train and Certify
    • Get Started in Cyber
    • Courses & Certifications
    • Training Roadmap
    • Search For Training
    • Online Training
    • OnDemand
    • Live Training
    • Summits
    • Cyber Ranges
    • College Degrees & Certificates
    • NICE Framework
    • DoDD 8140
    • Specials
  • Manage Your Team
    • Overview
    • Group Purchasing
    • Why Work with SANS
    • Build Your Team
    • Hire Cyber Talent
    • Team Development
    • Private Training
    • Security Awareness Training
    • Leadership Training
    • Industries
  • Resources
    • Overview
    • Reading Room
    • Webcasts
    • Newsletters
    • Blog
    • Tip of The Day
    • Posters
    • Top 25 Programming Errors
    • Security Policy Project
    • Critical Vulnerability Recaps
    • Affiliate Directory
  • Focus Areas
    • Blue Team Operations
    • Cloud Security
    • Digital Forensics & Incident Response
    • Industrial Control Systems
    • Leadership
    • Offensive Operations
  • Get Involved
    • Overview
    • Work Study
    • Teach for SANS
    • Partnerships
    • Sponsorship Opportunities
    • Join the Community
  • About
    • About SANS
    • Instructors
    • Mission
    • Initiatives
    • Diversity
    • Awards
    • Contact
    • Frequently Asked Questions
    • Customer Reviews
    • Press
  • Log In
  • Join
  • Contact Us
  • SANS Sites
    • GIAC Security Certifications
    • Internet Storm Center
    • SANS Technology Institute
    • Security Awareness Training
  • Search
  1. Home >
  2. Blog >
  3. Data recovery with Hex Editor and RegEx
Quinn Shamblin

Data recovery with Hex Editor and RegEx

April 10, 2009

In my previous post about recovering mp3 data from a corrupted chip, I describe a data recovery challenge that I could not solve using FTK, Foremost or Lazarus. It turned out that Regular Expressions were my answer. But how best to run regex-based data extraction against a forensic image when there might be hundreds of thousands, if not millions, of individual matching frames?

Hex Editor Neo was exactly what I needed. It has a few unique features that really differentiate the product. (1) it supports regular expressions as a possible selection input and (2) it allows for multi-selection.

The procedure I used pulled roughly 600 MB of pristine mp3 data off of a 1 GB image of a corrupted compact flash chip in around 30 seconds and I was left with a nice playable result. This technique will even remove non-mp3 data that may be present in between frames on the media.

This technique does not rely or reference meta data and will therefore not recognize a break point if there are supposed to be more than one MP3 on the image you are analyzing. But if mp3 data matching the criteria discussed in my previous post is present and is in sequential order, this process should pull it out for you nicely. Obviously, you may need to review the results in an audio editor like Audacity to work with what you have recovered and split it into separate files if needed.

(Note you will need to buy a license or to start up the 14-day full-feature evaluation version to do this. Some of the required features are disabled in the free version. It isn't expensive though.)

MP3 Frame Extraction Procedure:

  1. Open a copy of the source image file using Hex Editor Neo
  2. Press <cntl+F> to enter the Find function
  3. Enter all the parameters as shown to do a Regular Expression search.
    The RegEx string I needed for my data was: \xff\xfb(\x90.{414}|\x92.{415})
    ssheneofind.gif

    but if you have a different bit rate or other quality item, you may need a different RegEx. See the MPEG Audio Frame Header Specs for details on the header string and then use my results above and this RegEx Reference to construct one that will meet your needs.

  4. Press <cntl+i> to invert selection thereby selecting all non-mp3 frame data
  5. Press <delete> to remove the non-mp3 frame data. What is left is just the mp3 frames that meet your criteria, in sequence as found on the media
  6. Save as <filename>.mp3
  7. Proceed with subsequent review and analysis of resulting file

Quinn Shamblin (quinn.shamblin@uc.edu), GCFA Silver #2801, Investigator, University of Cincinnati Information Security


Share:
TwitterLinkedInFacebook
Copy url Url was copied to clipboard
Subscribe to SANS Newsletters
Join the SANS Community to receive the latest curated cybersecurity news, vulnerabilities, and mitigations, training opportunities, plus our webcast schedule.
United States
Canada
United Kingdom
Spain
Belgium
Denmark
Norway
Netherlands
Australia
India
Japan
Singapore
Afghanistan
Aland Islands
Albania
Algeria
American Samoa
Andorra
Angola
Anguilla
Antarctica
Antigua and Barbuda
Argentina
Armenia
Aruba
Austria
Azerbaijan
Bahamas
Bahrain
Bangladesh
Barbados
Belarus
Belize
Benin
Bermuda
Bhutan
Bolivia
Bonaire, Sint Eustatius, and Saba
Bosnia And Herzegovina
Botswana
Bouvet Island
Brazil
British Indian Ocean Territory
Brunei Darussalam
Bulgaria
Burkina Faso
Burundi
Cambodia
Cameroon
Cape Verde
Cayman Islands
Central African Republic
Chad
Chile
China
Christmas Island
Cocos (Keeling) Islands
Colombia
Comoros
Cook Islands
Costa Rica
Croatia (Local Name: Hrvatska)
Curacao
Cyprus
Czech Republic
Democratic Republic of the Congo
Djibouti
Dominica
Dominican Republic
East Timor
East Timor
Ecuador
Egypt
El Salvador
Equatorial Guinea
Eritrea
Estonia
Ethiopia
Falkland Islands (Malvinas)
Faroe Islands
Fiji
Finland
France
French Guiana
French Polynesia
French Southern Territories
Gabon
Gambia
Georgia
Germany
Ghana
Gibraltar
Greece
Greenland
Grenada
Guadeloupe
Guam
Guatemala
Guernsey
Guinea
Guinea-Bissau
Guyana
Haiti
Heard And McDonald Islands
Honduras
Hong Kong
Hungary
Iceland
Indonesia
Iraq
Ireland
Isle of Man
Israel
Italy
Jamaica
Jersey
Jordan
Kazakhstan
Kenya
Kingdom of Saudi Arabia
Kiribati
Korea, Republic Of
Kosovo
Kuwait
Kyrgyzstan
Lao People's Democratic Republic
Latvia
Lebanon
Lesotho
Liberia
Liechtenstein
Lithuania
Luxembourg
Macau
Macedonia
Madagascar
Malawi
Malaysia
Maldives
Mali
Malta
Marshall Islands
Martinique
Mauritania
Mauritius
Mayotte
Mexico
Micronesia, Federated States Of
Moldova, Republic Of
Monaco
Mongolia
Montenegro
Montserrat
Morocco
Mozambique
Myanmar
Namibia
Nauru
Nepal
Netherlands Antilles
New Caledonia
New Zealand
Nicaragua
Niger
Nigeria
Niue
Norfolk Island
Northern Mariana Islands
Oman
Pakistan
Palau
Palestine
Panama
Papua New Guinea
Paraguay
Peru
Philippines
Pitcairn
Poland
Portugal
Puerto Rico
Qatar
Reunion
Romania
Russian Federation
Rwanda
Saint Bartholemy
Saint Kitts And Nevis
Saint Lucia
Saint Martin
Saint Vincent And The Grenadines
Samoa
San Marino
Sao Tome And Principe
Senegal
Serbia
Seychelles
Sierra Leone
Sint Maarten
Slovakia (Slovak Republic)
Slovenia
Solomon Islands
South Africa
South Georgia and the South Sandwich Islands
South Sudan
Sri Lanka
St. Helena
St. Pierre And Miquelon
Suriname
Svalbard And Jan Mayen Islands
Swaziland
Sweden
Switzerland
Taiwan
Tajikistan
Tanzania
Thailand
Togo
Tokelau
Tonga
Trinidad And Tobago
Tunisia
Turkey
Turkmenistan
Turks And Caicos Islands
Tuvalu
Uganda
Ukraine
United Arab Emirates
United States Minor Outlying Islands
Uruguay
Uzbekistan
Vanuatu
Vatican City
Venezuela
Vietnam
Virgin Islands (British)
Virgin Islands (U.S.)
Wallis And Futuna Islands
Western Sahara
Yemen
Yugoslavia
Zambia
Zimbabwe

Tags:
  • Digital Forensics and Incident Response

Related Content

Blog
New_to_Cyber_Tanya_Janca.jpg
Digital Forensics and Incident Response, Cyber Defense Essentials, Penetration Testing and Ethical Hacking, Blue Team Operations, Cloud Security, Security Awareness
April 22, 2021
A Visual Summary of SANS New to Cyber Summit
The first-ever SANS New to Cyber Summit was a free, virtual event for the community. Check out these graphic recordings created in real-time throughou
No Headshot Available
Alison Kim
read more
Blog
3_Min_Max_(59).png
Digital Forensics and Incident Response, Cloud Security
April 9, 2021
NEW FOR509: Enterprise Cloud Forensics & Incident Response - Beta coming June 2021
The new Enterprise Cloud Forensics course brings examiners up to speed with the rapidly changing world of enterprise cloud
SANS DFIR
read more
Blog
3_Min_Max_(58).png
Digital Forensics and Incident Response
March 30, 2021
3MinMax Series Topic Review - Apple Acquisition
Apple devices that we must be aware of in order to perform forensic acquisitions
370x370_Kevin-Ripa.jpg
Kevin Ripa
read more
  • Register to Learn
  • Courses
  • Certifications
  • Degree Programs
  • Cyber Ranges
  • Job Tools
  • Security Policy Project
  • Posters
  • White Papers
  • Focus Areas
  • Blue Team Operations
  • Cloud Security
  • Cybersecurity Leadership
  • Digital Forensics
  • Industrial Control Systems
  • Offensive Operations
Subscribe to SANS Newsletters
Join the SANS Community to receive the latest curated cybersecurity news, vulnerabilities, and mitigations, training opportunities, plus our webcast schedule.
United States
Canada
United Kingdom
Spain
Belgium
Denmark
Norway
Netherlands
Australia
India
Japan
Singapore
Afghanistan
Aland Islands
Albania
Algeria
American Samoa
Andorra
Angola
Anguilla
Antarctica
Antigua and Barbuda
Argentina
Armenia
Aruba
Austria
Azerbaijan
Bahamas
Bahrain
Bangladesh
Barbados
Belarus
Belize
Benin
Bermuda
Bhutan
Bolivia
Bonaire, Sint Eustatius, and Saba
Bosnia And Herzegovina
Botswana
Bouvet Island
Brazil
British Indian Ocean Territory
Brunei Darussalam
Bulgaria
Burkina Faso
Burundi
Cambodia
Cameroon
Cape Verde
Cayman Islands
Central African Republic
Chad
Chile
China
Christmas Island
Cocos (Keeling) Islands
Colombia
Comoros
Cook Islands
Costa Rica
Croatia (Local Name: Hrvatska)
Curacao
Cyprus
Czech Republic
Democratic Republic of the Congo
Djibouti
Dominica
Dominican Republic
East Timor
East Timor
Ecuador
Egypt
El Salvador
Equatorial Guinea
Eritrea
Estonia
Ethiopia
Falkland Islands (Malvinas)
Faroe Islands
Fiji
Finland
France
French Guiana
French Polynesia
French Southern Territories
Gabon
Gambia
Georgia
Germany
Ghana
Gibraltar
Greece
Greenland
Grenada
Guadeloupe
Guam
Guatemala
Guernsey
Guinea
Guinea-Bissau
Guyana
Haiti
Heard And McDonald Islands
Honduras
Hong Kong
Hungary
Iceland
Indonesia
Iraq
Ireland
Isle of Man
Israel
Italy
Jamaica
Jersey
Jordan
Kazakhstan
Kenya
Kingdom of Saudi Arabia
Kiribati
Korea, Republic Of
Kosovo
Kuwait
Kyrgyzstan
Lao People's Democratic Republic
Latvia
Lebanon
Lesotho
Liberia
Liechtenstein
Lithuania
Luxembourg
Macau
Macedonia
Madagascar
Malawi
Malaysia
Maldives
Mali
Malta
Marshall Islands
Martinique
Mauritania
Mauritius
Mayotte
Mexico
Micronesia, Federated States Of
Moldova, Republic Of
Monaco
Mongolia
Montenegro
Montserrat
Morocco
Mozambique
Myanmar
Namibia
Nauru
Nepal
Netherlands Antilles
New Caledonia
New Zealand
Nicaragua
Niger
Nigeria
Niue
Norfolk Island
Northern Mariana Islands
Oman
Pakistan
Palau
Palestine
Panama
Papua New Guinea
Paraguay
Peru
Philippines
Pitcairn
Poland
Portugal
Puerto Rico
Qatar
Reunion
Romania
Russian Federation
Rwanda
Saint Bartholemy
Saint Kitts And Nevis
Saint Lucia
Saint Martin
Saint Vincent And The Grenadines
Samoa
San Marino
Sao Tome And Principe
Senegal
Serbia
Seychelles
Sierra Leone
Sint Maarten
Slovakia (Slovak Republic)
Slovenia
Solomon Islands
South Africa
South Georgia and the South Sandwich Islands
South Sudan
Sri Lanka
St. Helena
St. Pierre And Miquelon
Suriname
Svalbard And Jan Mayen Islands
Swaziland
Sweden
Switzerland
Taiwan
Tajikistan
Tanzania
Thailand
Togo
Tokelau
Tonga
Trinidad And Tobago
Tunisia
Turkey
Turkmenistan
Turks And Caicos Islands
Tuvalu
Uganda
Ukraine
United Arab Emirates
United States Minor Outlying Islands
Uruguay
Uzbekistan
Vanuatu
Vatican City
Venezuela
Vietnam
Virgin Islands (British)
Virgin Islands (U.S.)
Wallis And Futuna Islands
Western Sahara
Yemen
Yugoslavia
Zambia
Zimbabwe
  • © 2021 SANS™ Institute
  • Privacy Policy
  • Contact
  • Twitter
  • Facebook
  • Youtube
  • LinkedIn