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Armstrong Atlantic State University – Cyber & Homeland Security Institute. Covert Channels The Silence Must be Heard The Hidden Must be Seen The Secrets Must be Revealed By: Randy Grubb. Cyber Capabilities.
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Armstrong Atlantic State University – Cyber & Homeland Security Institute Covert Channels The Silence Must be Heard The Hidden Must be Seen The Secrets Must be Revealed By: Randy Grubb
Cyber Capabilities • By the turn of the century all known terrorist and criminal groups had a presence on the Internet. • Psychological Warfare • Propaganda • Data Mining • Fundraising/financing • Recruiting • Networking • Information sharing • Planning & coordination • Actual perpetration of their crimes
Why the Internet? • Anonymous (real or perceived) • Encryption • Covert Channels/Steganography • Public libraries/Internet cafes/wireless access points • Anonymizers/Proxies (Tor) • Geographically Unbounded • People can communicate with one another from virtually anywhere in the world • More than 10,000 Internet Service Providers (ISP) worldwide • Some are sympathetic to the radical cause
Why the Internet? • Largely unregulated • Developed as an open interoperable network • No central government authority • Most ISPs do not have the resources or desire to monitor web-site content • Inexpensive • Free web hosting • Free e-mail accounts
Why the Internet? • US and coalition military actions since 9/11 have deprived terrorist organizations their base of operations and training camps. • These actions have dispersed terrorist organizations more widely. • With the Internet, terrorist organizations can control a worldwide movement without ever meeting. Source: Harvard Gazette: Terror Online and how to counteract it, Ruth Walker, 2004
Netwar • Term given to an emerging mode of conflict dealing with the societal relationships between namely terrorists and criminal organizations. • Involves measures short of traditional warfare • Network forms of organization, doctrine, strategy and communication • Dispersed and decentralized manner
Netwar • Small groups from points around the world utilizing network and Internet technology to: • Communicate • Coordinate • Act
What are Covert Channels? • Covert Channels • Any communication channel that can be exploited by a process to transfer information in a manner that violates the systems security policy. • In short, covert channels transfer information using non-standard methods • Against the system design • Communication is obscured; unnoticed • Easily bypass current security tools & products
What are Covert Channels? • Covert Channels allow multiple parties to communicate ‘unseen’ • They hide the fact that a communication is even occurring • Provides privacy and anonymity • Unlike encryption, where communication is obvious but obscured • Encryption is easily identified • Clear and visible indications of encryption
Covert Channels • Covert Channels work because of human deficiencies • Eye sight • Hearing • Analysis skills • Lack of Interest • It’s not really a problem, doesn’t happen • Prove it to me • System Design Discrepancies • Components utilized in unintended manner
Covert Channels • Many covert channels will elude detection simply because most individuals have never considered the possibility • Perception over rides reality
Covert Channels • Covert Channels hide the fact that communication between two or more individuals is occurring.
Potential Damage • Corporate Espionage • Loss of competitive advantage • Government or Military Activities • Increased threat to National Security • Terrorist Organizations • Criminal Activities • Transfer of pornography or commercial software • Financial Impact • Transfer of confidential financial data
Known Covert Methods • Steganography • Images • Audio • Text Manipulation • TCP Covert Channels • Alternate Data Streams (ADS) • Deep or invisible web
Tool Summary • Over 300 known tool variation and releases • Tools for every Operating System including DOS, Windows, UNIX/Linux, OS2, Mac • Wide variety of methodologies and features • Most software is freeware or shareware
Origins of Steganography • What does Steganography Mean? • Pronounced “STEHG-uh-NAH-gru-fee” • From the Greek Roots • “Steganos” or Covered • “Graphie” or Writing • “Covered Writing” • First Known Usage • The early Greeks and Persians used several forms of covered writing to conceal the communication of secret or covert messages • Origins date back as far 2500 years ago
Carrier + Payload = Covert Message • Carrier – The file that provides cover for and conceals the payload. Payload – The secret message or information that you wish to conceal or communicate. • Covert Message – The combination of the payload and the carrier. The covert message file should appear identical to the carrier. • Most current stego tools also encrypt the payload to increase security.
Digital Images • Digital Images are created by software • Digital camera • Scanner • Graphics program • Digital Images are made up of pixels • Represented on a grid • The pixel is the smallest visual component • Resolution & representation • 640 x 480 – rows x columns • 75 dpi – number of dots per inch 1 Source: WetStone Technologies 1 http://www.library.cornell.edu/preservation/tutorial/intro/intro-01.html
Digital Images • Color is represented in digital images by three different methods. • Paletted images • True color images • Compressed images
Palette Images • Map to a pre-defined color on a table • Pixel represented by table lookup value 2 Source: WetStone Technologies 2http://www.webstyleguide.com/graphics/displays.html
True Color Images • True Color images • Typically 24 bits • Most common format is RGB or Red – Green - Blue • 8 bits for each color byte (red, green, blue) • 16.7M possible colors 4 Source: WetStone Technologies 4http://www.webstyleguide.com/graphics/displays.html
Least Significant Bit Steganography “The hiding of data within a digital carrier by slightly altering an insignificant characteristic of the carrier that does not appear to alter the normal rendering of the data” Hosmer, 1999 Source: WetStone Technologies
Altering a True Color Image 2 Image source: www.wikipedia.com 2http://www.webstyleguide.com/graphics/displays.html
1 0 1 1 0 1 0 1 0 1 0 LSB Substitution – bit 0 LSB Substitution Individual Colors Before After Combined Color 0 RED Before After GREEN 1 1 0 0 0 1 1 0 1 1 1 0 0 0 0 1 BLUE Source: WetStone Technologies
1 0 1 1 0 1 0 1 0 1 0 LSB Substitution bit 0 and 1 LSB Substitution Individual Colors Before After Combined Color 1 RED Before After GREEN 1 1 0 0 0 1 0 0 1 1 1 0 0 0 1 1 BLUE Source: WetStone Technologies
0 1 0 LSB Substitution bits (0-3) LSB Substitution Individual Colors Before After Combined Color 1 0 1 1 1 0 1 0 1 RED Before After GREEN 1 1 0 0 1 0 0 0 1 1 1 0 1 1 1 1 BLUE Source: WetStone Technologies
Color Differences Source: WetStone Technologies
Color Differences Source: WetStone Technologies
Color Differences Can you spot the modified pixel? Source: WetStone Technologies