CAPEC-649: Adding a Space to a File Extension (Version 3.9)
Archived: 2026-04-05 16:38:04 UTC
 Description
An adversary adds a space character to the end of a file extension and takes advantage of an application that does not
properly neutralize trailing special elements in file names. This extra space, which can be difficult for a user to notice,
affects which default application is used to operate on the file and can be leveraged by the adversary to control execution.
 Likelihood Of Attack
 Typical Severity
 Relationships
This table shows the other attack patterns and high level categories that are related to this attack pattern. These
relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels
of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack
patterns that the user may want to explore.
Nature Type
ChildOf Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It
This table shows the views that this attack pattern belongs to and top level categories within that view.
 Prerequisites
The use of the file must be controlled by the file extension.
 Consequences
This table specifies different individual consequences associated with the attack pattern. The Scope identifies the security
property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in
their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative
to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a
certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope Impact Likelihood
Confidentiality
Integrity
Availability
Execute Unauthorized Commands
 Mitigations
File extensions should be checked to see if non-visible characters are being included.
 Taxonomy Mappings
CAPEC mappings to ATT&CK techniques leverage an inheritance model to streamline and minimize direct
CAPEC/ATT&CK mappings. Inheritance of a mapping is indicated by text stating that the parent CAPEC has relevant
ATT&CK mappings. Note that the ATT&CK Enterprise Framework does not use an inheritance model as part of the
mapping to CAPEC.
Relevant to the ATT&CK taxonomy mapping (also see parent)
Entry ID Entry Name
1036.006 Masquerading:Space after Filename
https://capec.mitre.org/data/definitions/649.html
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Content History
Submissions
Submission Date Submitter Organization
2018-05-31
(Version 2.11)
CAPEC Content Team The MITRE Corporation
Modifications
Modification Date Modifier Organization
2019-04-04
(Version 3.1)
CAPEC Content Team The MITRE Corporation
Updated Related_Weaknesses
2020-07-30
(Version 3.3)
CAPEC Content Team The MITRE Corporation
Updated Taxonomy_Mappings
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Source: https://capec.mitre.org/data/definitions/649.html
https://capec.mitre.org/data/definitions/649.html
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