Adversaries may embed payloads within other files to conceal malicious content from defenses. Otherwise seemingly benign files (such as scripts and executables) may be abused to carry and obfuscate malicious payloads and content. In some cases, embedded payloads may also enable adversaries to Subvert Trust Controls by not impacting execution controls such as digital signatures and notarization tickets.(Citation: Sentinel Labs)
Adversaries may embed payloads in various file formats to hide payloads.(Citation: Microsoft Learn) This is similar to Steganography, though does not involve weaving malicious content into specific bytes and patterns related to legitimate digital media formats.(Citation: GitHub PSImage)
For example, adversaries have been observed embedding payloads within or as an overlay of an otherwise benign binary.(Citation: Securelist Dtrack2) Adversaries have also been observed nesting payloads (such as executables and run-only scripts) inside a file of the same format.(Citation: SentinelLabs reversing run-only applescripts 2021)
Embedded content may also be used as Process Injection payloads used to infect benign system processes.(Citation: Trend Micro) These embedded then injected payloads may be used as part of the modules of malware designed to provide specific features such as encrypting C2 communications in support of an orchestrator module. For example, an embedded module may be injected into default browsers, allowing adversaries to then communicate via the network.(Citation: Malware Analysis Report ComRAT)
Detection Strategy for Embedded Payloads
Antivirus/Antimalware: Antivirus/Antimalware solutions utilize signatures, heuristics, and behavioral analysis to detect, block, and remediate malicious software, including viruses, trojans, ransomware, and spyware. These solutions continuously monitor endpoints and systems for known malicious patterns and suspicious behaviors that indicate compromise. Antivirus/Antimalware software should be deployed across all devices, with automated updates to ensure protection against the latest threats. This mitigation can be implemented through the following measures:
Signature-Based Detection:
Heuristic-Based Detection:
Behavioral Detection (Behavior Prevention):
Real-Time Scanning:
Cloud-Assisted Threat Intelligence:
Tools for Implementation:
Behavior Prevention on Endpoint: Behavior Prevention on Endpoint refers to the use of technologies and strategies to detect and block potentially malicious activities by analyzing the behavior of processes, files, API calls, and other endpoint events. Rather than relying solely on known signatures, this approach leverages heuristics, machine learning, and real-time monitoring to identify anomalous patterns indicative of an attack. This mitigation can be implemented through the following measures:
Suspicious Process Behavior:
Unauthorized File Access:
Abnormal API Calls:
OpenProcess and WriteProcessMemory and terminates the offending process.Exploit Prevention: