IFEO Injection
What is IFEO?
Image File Execution Options (IFEO) is a Windows registry feature that allows debugging configurations for executable files. It is primarily intended for developers and debugging tools but can be exploited by attackers to execute malicious code transparently when specific applications are launched.
Registry Path for IFEO:
HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\<executable_name>Within this key, setting a Debugger value causes Windows to invoke the specified debugger instead of the original executable.
How Attackers Abuse IFEO
By modifying the registry, an attacker can set a malicious debugger for a trusted application. When a user launches that application, the malicious code executes instead or alongside the legitimate process.
Common Attack Scenarios:
Process Replacement: Replacing a legitimate process with a malicious one.
Persistence: Maintaining system access by ensuring malicious code runs whenever a specific application is opened.
Command Injection: Launching malicious commands or scripts during application startup.
Example of an IFEO Attack
PowerShell Script to Set a Malicious Debugger for Notepad:
# Define the registry path for notepad.exe
$RegistryPath = "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\notepad.exe"
# Create the registry key if it doesn't exist
New-Item -Path $RegistryPath -Force | Out-Null
# Set the Debugger value to a malicious payload (replace with actual payload)
New-ItemProperty -Path $RegistryPath -Name "Debugger" -Value "C:\Path\To\Malicious\payload.exe" -PropertyType StringAlternatively, via command line:
When a user launches Notepad, the system executes the malicious payload instead.
Vulnerabilities in Desktop Applications via IFEO
Certain desktop applications are vulnerable to IFEO injection if they do not validate or restrict registry modifications. Common vulnerable applications include:
System Utilities: Notepad, Calculator, Paint
Third-party Productivity Apps: Microsoft Office components, Adobe Reader
Development Tools: Visual Studio, IDEs
Vulnerable Scenario:
An attacker modifies the IFEO Debugger key for calc.exe (Calculator). When a user opens Calculator, the malicious code executes, potentially installing backdoors or stealing data.
Real-World Attack Example
Suppose an attacker wants to hijack Notepad:
They add a registry key:
When any user opens Notepad, trojan.exe runs instead or alongside, allowing the attacker to perform actions such as:
Establishing persistence
Executing further malicious payloads
Escalating privileges
Defense and Mitigation
Monitor Registry Changes: Use security tools or policies to detect modifications in IFEO paths.
Restrict Permissions: Limit write access to registry keys related to IFEO.
Disable Debugger Settings: For critical systems, consider disabling debugging features.
Application Whitelisting: Only allow trusted applications to modify registry entries.
User Education: Train users to recognize suspicious activity related to application launches.
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