Analysis

  • max time kernel
    15s
  • max time network
    112s
  • platform
    windows10_x64
  • resource
    win10v20201028
  • submitted
    04/03/2021, 20:07

General

  • Target
    OfficeDocument.exe
  • Size 279KB
  • Sample210304-dvs4y84q2a
  • SHA256 0e735a5773b8aa36e2a596ea6e468d75038db7dd644236b4eb745b66762f4ebf
  • MD5 SHA1 SHA512
Score
10/10

Malware Config

Extracted

Family
  • buer

C2
  • grandbanking-api.com

Signatures

  • Buer

    Buer is a new modular loader first seen in August 2019.

  • Buer Loader 1 IoCs

    Detects Buer loader in memory or disk.

  • Loads dropped DLL 1 IoCs
  • Suspicious use of SetThreadContext 1 IoCs
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

  • Suspicious behavior: MapViewOfSection 1 IoCs
  • Suspicious use of WriteProcessMemory 4 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe
    "C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe"
    1⤵
    • Loads dropped DLL
    • Suspicious use of SetThreadContext
    • Suspicious behavior: MapViewOfSection
    • Suspicious use of WriteProcessMemory
    PID:4652
    • C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe
      "C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe"
      2⤵
        PID:3308

    Network

          MITRE ATT&CK Enterprise v6

          Replay Monitor

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          Downloads

          memory/3308-4-0x0000000040000000-0x0000000040009000-memory.dmp