Analysis

  • max time kernel
    13s
  • max time network
    12s
  • platform
    windows7_x64
  • resource
    win7v20201028
  • submitted
    04-03-2021 20:07

General

  • Target

    OfficeDocument.exe

  • Size

    279KB

  • MD5

    b04e5c4ad1bc75a4a0cd5686e869acdb

  • SHA1

    8a8fadeb752362fb265baa83f690bc4250556d33

  • SHA256

    0e735a5773b8aa36e2a596ea6e468d75038db7dd644236b4eb745b66762f4ebf

  • SHA512

    c06212a009af916a8dd707eca6d1e24cf28ce6b8726b51663562cbf1598138aef5d02b13c3ba2ad5c56940ddb47558224d6d7aa752347e0321267791e7141cfa

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 8 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:324
    • C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe
      "C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe"
      2⤵
        PID:1276

    Network

    MITRE ATT&CK Matrix ATT&CK v6

    Discovery

    System Information Discovery

    1
    T1082

    Replay Monitor

    Loading Replay Monitor...

    Downloads

    • \Users\Admin\AppData\Local\Temp\nss4C9B.tmp\System.dll
      MD5

      0063d48afe5a0cdc02833145667b6641

      SHA1

      e7eb614805d183ecb1127c62decb1a6be1b4f7a8

      SHA256

      ac9dfe3b35ea4b8932536ed7406c29a432976b685cc5322f94ef93df920fede7

      SHA512

      71cbbcaeb345e09306e368717ea0503fe8df485be2e95200febc61bcd8ba74fb4211cd263c232f148c0123f6c6f2e3fd4ea20bdecc4070f5208c35c6920240f0

    • memory/324-2-0x00000000766C1000-0x00000000766C3000-memory.dmp
      Filesize

      8KB

    • memory/1276-4-0x0000000040005EFA-mapping.dmp
    • memory/1276-5-0x0000000040000000-0x0000000040009000-memory.dmp
      Filesize

      36KB