Analysis

  • max time kernel
    13s
  • max time network
    9s
  • platform
    windows7_x64
  • resource
    win7-20240903-en
  • resource tags

    arch:x64arch:x86image:win7-20240903-enlocale:en-usos:windows7-x64system
  • submitted
    13-09-2024 14:44

General

  • Target

    AA_v3.exe

  • Size

    798KB

  • MD5

    90aadf2247149996ae443e2c82af3730

  • SHA1

    050b7eba825412b24e3f02d76d7da5ae97e10502

  • SHA256

    ee573647477339784dcef81024de1be1762833a20e5cc2b89a93e47d05b86b6a

  • SHA512

    eec32bb82b230dd309c29712e72d4469250e651449e127479d178eddbafd5a46ec8048a753bc2c1a0fdf1dc3ed72a9453ca66fb49cbf0f95a12704e5427182be

  • SSDEEP

    24576:Uj0JJ4p/A4npt3XojeQG5EtzRtO7GvmDguXd:UjoJ4u4zojegylDN

Malware Config

Signatures

  • FlawedAmmyy RAT

    Remote-access trojan based on leaked code for the Ammyy remote admin software.

  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Loads dropped DLL 4 IoCs
  • Writes to the Master Boot Record (MBR) 1 TTPs 2 IoCs

    Bootkits write to the MBR to gain persistence at a level below the operating system.

  • Drops file in System32 directory 5 IoCs
  • System Location Discovery: System Language Discovery 1 TTPs 3 IoCs

    Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

  • Modifies data under HKEY_USERS 64 IoCs
  • Modifies system certificate store 2 TTPs 2 IoCs
  • Suspicious use of FindShellTrayWindow 1 IoCs
  • Suspicious use of SendNotifyMessage 1 IoCs
  • Suspicious use of WriteProcessMemory 8 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\AA_v3.exe
    "C:\Users\Admin\AppData\Local\Temp\AA_v3.exe"
    1⤵
    • Writes to the Master Boot Record (MBR)
    • System Location Discovery: System Language Discovery
    PID:2160
  • C:\Users\Admin\AppData\Local\Temp\AA_v3.exe
    "C:\Users\Admin\AppData\Local\Temp\AA_v3.exe" -service -lunch
    1⤵
    • System Location Discovery: System Language Discovery
    • Suspicious use of WriteProcessMemory
    PID:1108
    • C:\Users\Admin\AppData\Local\Temp\AA_v3.exe
      "C:\Users\Admin\AppData\Local\Temp\AA_v3.exe"
      2⤵
      • Checks computer location settings
      • Writes to the Master Boot Record (MBR)
      • Drops file in System32 directory
      • System Location Discovery: System Language Discovery
      • Modifies data under HKEY_USERS
      • Modifies system certificate store
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of SendNotifyMessage
      • Suspicious use of WriteProcessMemory
      PID:3068
      • C:\Windows\system32\rundll32.exe
        rundll32.exe "C:\ProgramData\AMMYY\aa_nts.dll",run
        3⤵
        • Loads dropped DLL
        PID:2784

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

  • C:\ProgramData\AMMYY\aa_nts.dll

    Filesize

    902KB

    MD5

    480a66902e6e7cdafaa6711e8697ff8c

    SHA1

    6ac730962e7c1dba9e2ecc5733a506544f3c8d11

    SHA256

    7eaaaa6010bbcd6bb8c9ad08d4b0966c7aedc9b2ac24758f170012ac36e508b5

    SHA512

    7d010cd47b7d1adf66f9c97afc6c3805997aa5c7cc6ff13eddee81f24cf2b95a3fe375ec5b3d6185c0bc8840b4ad91ae143c73a39af26391cc182ab6a1793ba5

  • C:\ProgramData\AMMYY\aa_nts.msg

    Filesize

    46B

    MD5

    76038623e270f399769df67a3ed15c16

    SHA1

    ebf7d7537f45738be48e6f64d59c846b13fb4334

    SHA256

    4dbdf4f709d50f9521e92ce5f7d4f305e2384bcda387fb2b325ff17d205bb687

    SHA512

    a5316694d844e5b10c589f58fdf65645568b3909b2914f85c99195f9625e4124f787bc0980cff98f1e8289ff84824620a03f32cdab18e5bbcb2e59b33f397aec

  • C:\ProgramData\AMMYY\settings3.bin

    Filesize

    334B

    MD5

    307b8fa94d4e05bcefb9eaf530052d86

    SHA1

    1b35b3598b1f8ed7148893d2eb6a3ba416b113dc

    SHA256

    685190b35d6bf2b364732ed77191b0ac0a8d440ee7d9afdda20c48d6423cacb1

    SHA512

    d19c516d745634b72132264d4924473292b0ea75c67dd77d0079e1eb7a41ff2bf567c5c69787cc5b3d55e2059319748edf56393b989105aba24dbaa9c2ecb81d