Trojan Horse
Incomplete Base
Structure: Simple
Description
The product appears to contain benign or useful functionality, but it also contains code that is hidden from normal operation that violates the intended security policy of the user or the system administrator.
Common Consequences 1
Scope: ConfidentialityIntegrityAvailability
Impact: Execute Unauthorized Code or Commands
Potential Mitigations 2
Phase: Operation
Most antivirus software scans for Trojan Horses.
Phase: Installation
Verify the integrity of the product that is being installed.
References 2
Writing Secure Code
Michael Howard and David LeBlanc
Microsoft Press
04-12-2002
ID: REF-7
A Taxonomy of Computer Program Security Flaws, with Examples
Carl E. Landwehr, Alan R. Bull, John P. McDermott, and William S. Choi
19-11-1993
ID: REF-1431
Modes of Introduction
Implementation
Operation
Related Attack Patterns
Related Weaknesses
ChildOf:
Embedded Malicious Code (CWE-506)
Taxonomy Mapping
- Landwehr
Notes
OtherPotentially malicious dynamic code compiled at runtime can conceal any number of attacks that will not appear in the baseline. The use of dynamically compiled code could also allow the injection of attacks on post-deployed applications.
Terminology
Definitions of "Trojan horse" and related terms have varied widely over the years, but common usage in 2008 generally refers to software that performs a legitimate function, but also contains malicious code.
Almost any malicious code can be called a Trojan horse, since the author of malicious code needs to disguise it somehow so that it will be invoked by a nonmalicious user (unless the author means also to invoke the code, in which case they presumably already possess the authorization to perform the intended sabotage). A Trojan horse that replicates itself by copying its code into other program files (see case MA1) is commonly referred to as a virus. One that replicates itself by creating new processes or files to contain its code, instead of modifying existing storage entities, is often called a worm. Denning provides a general discussion of these terms; differences of opinion about the term applicable to a particular flaw or its exploitations sometimes occur.