Capemon Skills

capemon is a sophisticated monitoring and instrumentation engine designed for malware analysis, configuration extraction, and payload recovery. It acts as the core injection component for the CAPEv2 sandbox.

Core Capabilities

1. API Hooking & Monitoring

capemon implements an extensive hooking engine derived from cuckoomon-modified, providing deep visibility into application behavior across multiple subsystems:

• Process & Thread Management: Monitoring creation, termination, and manipulation of processes and threads.
• File System Operations: Tracking file creation, deletion, reading, and writing.
• Registry Activity: Capturing configuration changes and persistence mechanisms.
• Network Communication: Intercepting socket operations, DNS queries, and high-level protocol activity (HTTP, etc.).
• Cryptography: Extracting keys and monitoring encryption/decryption routines.
• Synchronization & Services: Monitoring mutexes, events, and Windows Service interactions.
• Windows Management Instrumentation (WMI): Intercepting WMI queries used for anti-analysis or reconnaissance.
• Scripting Engines: Specific hooks for VBScript and other language runtimes.

2. Debugging & Tracing

capemon implements a powerful in-process debugger independent of Windows debugging interfaces, but harnessing the capabilities of the processor:

• Hardware breakpoints: Four breakpoints bp0-bp3 that can be set on execute, read or write
• Software breakpoints: Unlimited INT3 or 'CC' breakpoints overwriting instruction byte
• Single-step: Tracing allows instruction-level capture enhanced with configurable step-over, trace-length, register changes, function names, strings & more
• Actions: Configurable actions allow control flow manipulation with skipped or taken jumps, arbitrary register changes or jumps, string capture, dumps, scans & more
• Programmable: Debugger configurable either on submission with simple text options or via dynamic YARA signature scans during unpacking or detonation
• Integration: Hooking engine integrated with optional behavior log output & breakpoints set on return from hooked APIs (break-on-return)
• Stealth: Debugger does not rely upon Windows interface and thus evades detection by a slew of interface-related indicators, with additional stealth from hook-based protections

3. Automated Unpacking

'capemon' implements a powerful unpacking engine using a combination of techniques

• Memory region tracking: Regions of memory revealed through indicators of execution, allocation or protection are tracked
• Early capture: Multiple possible triggers allow payload capture at earliest moment often resulting in working unpacked samples
• Injection capture:: Strong coverage of injection techniques for inter-process payload capture
• PE unmapping: Integrated Scylla engine allows capture of memory or file-mapped PE images in memory
• Shellcode dumping: Shellcode * non-PE regions equally captured as payloads
• Import Reconstruction: Repairing Import Address Tables (IAT) to create functional dumped executables.
• AMSI Dumping: Intercepting and dumping buffers passed to the Antimalware Scan Interface (AMSI).

4. Config Extraction

Automated Static & Dynamic malware configuration extraction relies on 'capemon' capabilities

• Static extraction: Typically reliant upon capemon's unpacking or process dump capture before static parsing
• Dynamic extraction: When parser implementation is onerous, dynamic capture of decrypted configs can be performed by debugger via YARA signature

5. YARA integration

Integration of YARA for in-memory scanning

• Dynamic configuration: Sandbox configuration such as hooking exclusions or options implemented during detonation
• Debugger programming: Precise dydnamic breakpoint address resolution using YARA signatures & cape-specific metadata
• Unpacking engine integration: Dynamic scanning of all memory regions prior to unpacking capture
• Function resolution: Allows dynamic address resolution for APIs or functions for hooking or other purposes

Technical Foundations

• Platform: Windows (x86 and x64).
• Hooking Method: Inline hooking of Win32 and Native APIs (NTAPI).
• Debugger: Native in-process 'self' debugging utilising minimal OS interfaces & hardware capabilities (breakpoint, single-step)
• Dependencies:
  • distorm for instruction decoding.
  • libyara for pattern matching.
  • Scylla for PE reconstruction.
  • bson for data serialization.