Detection of Malicious or Unauthorized Software Extensions

Technique Detected:  Software Extensions | T1176

ID: DET0092
Domains: Enterprise
Analytics: AN0251, AN0252, AN0253
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN0251

Installation or execution of a malicious browser or IDE extension, followed by abnormal registry entries or outbound network connections from the host application

Log Sources
Data Component Name Channel
Process Creation (DC0032) WinEventLog:Security EventCode=4688
File Creation (DC0039) WinEventLog:Sysmon EventCode=11
Windows Registry Key Modification (DC0063) WinEventLog:Sysmon EventCode=13
Network Connection Creation (DC0082) WinEventLog:Sysmon EventCode=3
Mutable Elements
Field Description
Image Path of browser or IDE launching subprocesses—may vary depending on installed applications
ParentImage Legitimate parent-child process relationships for known safe extensions
RegistryPath Expected registry keys under HKCU/HKLM for installed extensions
TimeWindow Tunable interval to correlate extension install with follow-on C2 traffic

AN0252

Installation of configuration profiles or plist entries associated with malicious or unauthorized browser extensions

Log Sources
Data Component Name Channel
Command Execution (DC0064) macos:unifiedlog Execution of 'profiles install -type=configuration'
File Creation (DC0039) macos:unifiedlog Creation of .plist under /Library/Managed Preferences/
Network Traffic Flow (DC0078) macos:unifiedlog Suspicious outbound traffic from browser binary to non-standard domains
Mutable Elements
Field Description
PlistPath Directory path for user-specific extension configuration files
CommandLine Usage of profiles CLI tool—can be modified by legitimate tools or MDMs
TimeWindow Correlation window between configuration install and observable extension behavior

AN0253

Manual or script-based installation of extension-like modules into browser config directories or IDE plugin paths, followed by suspicious network activity

Log Sources
Data Component Name Channel
Process Creation (DC0032) auditd:SYSCALL execve
File Creation (DC0039) fs:fileevents creat
Network Traffic Flow (DC0078) NSM:Flow Abnormal browser traffic volume or destination
Mutable Elements
Field Description
DirectoryPath Common plugin or extension directories may vary by distro or browser (e.g., ~/.config/google-chrome/Default/Extensions)
ExecPath Path to scripting tools used in installation (e.g., bash, curl, unzip)
TimeWindow Tunable interval between install and first network beacon