Analysis

  • max time kernel
    142s
  • max time network
    148s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20250129-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20250129-enlocale:en-usos:windows10-2004-x64system
  • submitted
    06-02-2025 18:49

General

  • Target

    krx/RUN THIS SCRIPT TO START KRX.bat.lnk

  • Size

    1KB

  • MD5

    4c86e93d580bdd34d6a789b0f46afab7

  • SHA1

    d6598b1ea15eefba1316a52a8ba721c77152f20c

  • SHA256

    cd531534cc3454ff81864230d94c8aa26952be3fe6e34dab128c23f71c3e5d56

  • SHA512

    fdfba0de21c8e65b59ebe2e0b96c97adb02da9766b8a30fb9bb1ce1a5ee46335e03f7b4c13a590351670638042b5a8d5065fe9c21fe2ce3108a39d53432d353a

Malware Config

Signatures

  • Detect Umbral payload 2 IoCs
  • Umbral

    Umbral stealer is an opensource moduler stealer written in C#.

  • Umbral family
  • Command and Scripting Interpreter: PowerShell 1 TTPs 5 IoCs

    Using powershell.exe command.

  • Drops file in Drivers directory 1 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

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

  • Executes dropped EXE 2 IoCs
  • Reads user/profile data of web browsers 3 TTPs

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

  • Unexpected DNS network traffic destination 30 IoCs

    Network traffic to other servers than the configured DNS servers was detected on the DNS port.

  • 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.

  • 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.

  • System Network Configuration Discovery: Internet Connection Discovery 1 TTPs 2 IoCs

    Adversaries may check for Internet connectivity on compromised systems.

  • Detects videocard installed 1 TTPs 1 IoCs

    Uses WMIC.exe to determine videocard installed.

  • Gathers network information 2 TTPs 1 IoCs

    Uses commandline utility to view network configuration.

  • Modifies registry class 1 IoCs
  • Runs ping.exe 1 TTPs 1 IoCs
  • Suspicious behavior: EnumeratesProcesses 18 IoCs
  • Suspicious use of AdjustPrivilegeToken 64 IoCs
  • Suspicious use of WriteProcessMemory 41 IoCs
  • Views/modifies file attributes 1 TTPs 1 IoCs

Processes

  • C:\Windows\system32\cmd.exe
    cmd /c "C:\Users\Admin\AppData\Local\Temp\krx\RUN THIS SCRIPT TO START KRX.bat.lnk"
    1⤵
    • Checks computer location settings
    • Modifies registry class
    • Suspicious use of WriteProcessMemory
    PID:4248
    • C:\Windows\System32\cmd.exe
      "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\krx\.RUN THIS SCRIPT TO START KRX.bat"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2052
      • C:\Windows\system32\openfiles.exe
        openfiles
        3⤵
          PID:2188
        • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
          powershell -ExecutionPolicy Bypass -NoProfile -File "C:\Users\Admin\AppData\Local\Temp\krx\.crack.ps1"
          3⤵
          • Command and Scripting Interpreter: PowerShell
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          PID:4720
        • C:\Windows\system32\ipconfig.exe
          ipconfig /flushdns
          3⤵
          • Gathers network information
          PID:3604
        • C:\Users\Admin\AppData\Local\Temp\krx\krx\KRX Client.exe
          "C:\Users\Admin\AppData\Local\Temp\krx\krx/KRX Client.exe"
          3⤵
          • System Location Discovery: System Language Discovery
          • Suspicious use of WriteProcessMemory
          PID:860
          • C:\Users\Admin\AppData\Local\Temp\Umbral.exe
            "C:\Users\Admin\AppData\Local\Temp\Umbral.exe"
            4⤵
            • Drops file in Drivers directory
            • Executes dropped EXE
            • Unexpected DNS network traffic destination
            • Suspicious behavior: EnumeratesProcesses
            • Suspicious use of AdjustPrivilegeToken
            • Suspicious use of WriteProcessMemory
            PID:4340
            • C:\Windows\System32\Wbem\wmic.exe
              "wmic.exe" csproduct get uuid
              5⤵
              • Suspicious use of AdjustPrivilegeToken
              PID:3332
            • C:\Windows\SYSTEM32\attrib.exe
              "attrib.exe" +h +s "C:\Users\Admin\AppData\Local\Temp\Umbral.exe"
              5⤵
              • Views/modifies file attributes
              PID:3240
            • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
              "powershell.exe" Add-MpPreference -ExclusionPath 'C:\Users\Admin\AppData\Local\Temp\Umbral.exe'
              5⤵
              • Command and Scripting Interpreter: PowerShell
              • Suspicious behavior: EnumeratesProcesses
              PID:5060
            • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
              "powershell.exe" Set-MpPreference -DisableIntrusionPreventionSystem $true -DisableIOAVProtection $true -DisableRealtimeMonitoring $true -DisableScriptScanning $true -EnableControlledFolderAccess Disabled -EnableNetworkProtection AuditMode -Force -MAPSReporting Disabled -SubmitSamplesConsent NeverSend && powershell Set-MpPreference -SubmitSamplesConsent 2
              5⤵
              • Command and Scripting Interpreter: PowerShell
              • Suspicious behavior: EnumeratesProcesses
              PID:3100
            • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
              "powershell.exe" Get-ItemPropertyValue -Path HKCU:SOFTWARE\Roblox\RobloxStudioBrowser\roblox.com -Name .ROBLOSECURITY
              5⤵
              • Command and Scripting Interpreter: PowerShell
              • Suspicious behavior: EnumeratesProcesses
              PID:4608
            • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
              "powershell.exe" Get-ItemPropertyValue -Path HKLN:SOFTWARE\Roblox\RobloxStudioBrowser\roblox.com -Name .ROBLOSECURITY
              5⤵
              • Suspicious behavior: EnumeratesProcesses
              PID:2520
            • C:\Windows\System32\Wbem\wmic.exe
              "wmic.exe" os get Caption
              5⤵
                PID:5036
              • C:\Windows\System32\Wbem\wmic.exe
                "wmic.exe" computersystem get totalphysicalmemory
                5⤵
                  PID:860
                • C:\Windows\System32\Wbem\wmic.exe
                  "wmic.exe" csproduct get uuid
                  5⤵
                    PID:2592
                  • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                    "powershell.exe" Get-ItemPropertyValue -Path 'HKLM:System\CurrentControlSet\Control\Session Manager\Environment' -Name PROCESSOR_IDENTIFIER
                    5⤵
                    • Command and Scripting Interpreter: PowerShell
                    • Suspicious behavior: EnumeratesProcesses
                    PID:1384
                  • C:\Windows\System32\Wbem\wmic.exe
                    "wmic" path win32_VideoController get name
                    5⤵
                    • Detects videocard installed
                    PID:2432
                  • C:\Windows\SYSTEM32\cmd.exe
                    "cmd.exe" /c ping localhost && del /F /A h "C:\Users\Admin\AppData\Local\Temp\Umbral.exe" && pause
                    5⤵
                    • System Network Configuration Discovery: Internet Connection Discovery
                    • Suspicious use of WriteProcessMemory
                    PID:4372
                    • C:\Windows\system32\PING.EXE
                      ping localhost
                      6⤵
                      • System Network Configuration Discovery: Internet Connection Discovery
                      • Runs ping.exe
                      PID:2644
                • C:\Users\Admin\AppData\Local\Temp\KRX Client.exe
                  "C:\Users\Admin\AppData\Local\Temp\KRX Client.exe"
                  4⤵
                  • Executes dropped EXE
                  PID:4980

          Network

          MITRE ATT&CK Enterprise v15

          Replay Monitor

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          Downloads

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

            Filesize

            3KB

            MD5

            84ad5ddb8558903f27ae91fe0564e7e1

            SHA1

            834133d4eeb2f4b2d793aa7994c57b015ab03d8a

            SHA256

            70d66b78d8176bbd71e89c07e16e9551b8ef848a0157216dc94ceaab66ef2930

            SHA512

            9c564f1ad5cc23a0ad1a0fb1b909f009e41b0ff3e7cdc3f7736622224cd8a49d0c8ad983ebaf3e745bfaf862dc0e7af6820082262a43c413dc7ef3d5af58f864

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

            Filesize

            1KB

            MD5

            276798eeb29a49dc6e199768bc9c2e71

            SHA1

            5fdc8ccb897ac2df7476fbb07517aca5b7a6205b

            SHA256

            cd0a1056e8f1b6cb5cb328532239d802f4e2aa8f8fcdc0fcb487684bd68e0dcc

            SHA512

            0d34fce64bbefc57d64fa6e03ca886952263d5f24df9c1c4cce6a1e8f5a47a9a21e9820f8d38caa7f7b43a52336ce00b738ea18419aaa7c788b72e04ce19e4f2

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

            Filesize

            1KB

            MD5

            ec79fae4e7c09310ebf4f2d85a33a638

            SHA1

            f2bdd995b12e65e7ed437d228f22223b59e76efb

            SHA256

            e9c4723a5fe34e081c3d2f548a1d472394cc7aa58056fcf44ca542061381243a

            SHA512

            af9dda12f6bb388d826fe03a4a8beed9bda23a978aa55a2af6a43271660ee896a7ee3bcf2c4d2f1e6180902791d8c23560f1c2ec097a501d8c6f4f6c49075625

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

            Filesize

            1KB

            MD5

            f224d2e7a9a04868f8ec6eb16baec5d9

            SHA1

            c095946cb45a48431d91af00e7095184cea9da6e

            SHA256

            99766979376b2b719b538626b75dcb01f4e26ef041985a33f51c22e0980754c4

            SHA512

            ff92a96212532ec9290286eb21c04c8f9fbc9b811fcdc9fea38720b0046f615cb6e7b3b024c8dbd54d4d7f39614f59fe9c2d7d0d94e64b910a6fca9c0720aceb

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

            Filesize

            944B

            MD5

            f19a5f4296f81c2199b2e1f8b009a3d3

            SHA1

            823927d82433a3fd382002417f053858007b8742

            SHA256

            1fbcae667e9ae2cfb33887b7c1f38bf652bde956b65c3ac5caa1419d45204d7e

            SHA512

            6d993130dc41d1ffef5505ea97fd6cec6223871f074c9340452884ccfa8ee85bdd0418ef144f30a84c6bd05b74ef477ab99fe6a6ccb3fe6e75cc88b52dff30ee

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

            Filesize

            948B

            MD5

            966914e2e771de7a4a57a95b6ecfa8a9

            SHA1

            7a32282fd51dd032967ed4d9a40cc57e265aeff2

            SHA256

            98d3c70d7004fa807897317bd6cd3e977b9b6c72d4d2565aca0f9f8b1c315cba

            SHA512

            dc39c7124a9c7c8d4c7e8e16290c46360b8d9a8f4e43edaacbbeb09bdcf20159a53db54d2b322372001b6a3de52b2f88e9088b5fdbc7638816ae0d122bb015f5

          • C:\Users\Admin\AppData\Local\Temp\KRX Client.exe

            Filesize

            13.4MB

            MD5

            7907e9406015ceba49d7f1156f032ac8

            SHA1

            a8034055f4358c1d687b3c2c70c588f37982fa88

            SHA256

            fc59d043ebbf8e3225f399030bc6447a0592e992bcb57a08d769c35934335de3

            SHA512

            bff798c9a2301120c343e7108a857dc2a78e5c18fa5fbc06d71ada65f96adbff3ce47e3ffbf51c13db50f0c09ae6d0bcad4a2abe3911e0bd0b2a1b816c0685a9

          • C:\Users\Admin\AppData\Local\Temp\Umbral.exe

            Filesize

            231KB

            MD5

            39866481d5925ad5fb5a6c72bc51c3c5

            SHA1

            6c646ec853a4178e219c73cd1788d3f51623099d

            SHA256

            38042abd98755c213a6f36e5c79d23e7d09b56495b29daab3e89fcdccde80ad2

            SHA512

            daca18d9d9132ffe07b142a80148aa98575c72052de8bd18115f85adcac1ed8b6f990a85d3076a9c88e934694ae8ba19b58eb6cf81bc27a3c84480c3e853779d

          • C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_y3airpqx.log.ps1

            Filesize

            60B

            MD5

            d17fe0a3f47be24a6453e9ef58c94641

            SHA1

            6ab83620379fc69f80c0242105ddffd7d98d5d9d

            SHA256

            96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

            SHA512

            5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

          • memory/4340-68-0x000001E297E50000-0x000001E297EC6000-memory.dmp

            Filesize

            472KB

          • memory/4340-69-0x000001E297ED0000-0x000001E297F20000-memory.dmp

            Filesize

            320KB

          • memory/4340-106-0x000001E296630000-0x000001E29663A000-memory.dmp

            Filesize

            40KB

          • memory/4340-107-0x000001E296680000-0x000001E296692000-memory.dmp

            Filesize

            72KB

          • memory/4340-32-0x000001E296130000-0x000001E296170000-memory.dmp

            Filesize

            256KB

          • memory/4340-70-0x000001E296600000-0x000001E29661E000-memory.dmp

            Filesize

            120KB

          • memory/4720-16-0x0000021743050000-0x000002174306A000-memory.dmp

            Filesize

            104KB

          • memory/4720-2-0x00007FFF38983000-0x00007FFF38985000-memory.dmp

            Filesize

            8KB

          • memory/4720-15-0x0000021742B40000-0x0000021742B50000-memory.dmp

            Filesize

            64KB

          • memory/4720-14-0x00007FFF38980000-0x00007FFF39441000-memory.dmp

            Filesize

            10.8MB

          • memory/4720-13-0x00007FFF38980000-0x00007FFF39441000-memory.dmp

            Filesize

            10.8MB

          • memory/4720-19-0x00007FFF38980000-0x00007FFF39441000-memory.dmp

            Filesize

            10.8MB

          • memory/4720-12-0x0000021742C80000-0x0000021742CA2000-memory.dmp

            Filesize

            136KB

          • memory/4980-42-0x0000000140000000-0x0000000142086000-memory.dmp

            Filesize

            32.5MB