Analysis

  • max time kernel
    31s
  • max time network
    35s
  • platform
    windows7_x64
  • resource
    win7-20221111-en
  • resource tags

    arch:x64arch:x86image:win7-20221111-enlocale:en-usos:windows7-x64system
  • submitted
    17-01-2023 01:01

General

  • Target

    HEUR-Trojan-Spy.MSIL.Stealer.gen-069818f3ba31.exe

  • Size

    1.4MB

  • MD5

    713e9e1e0c47b99a953ae2b751faf8d0

  • SHA1

    37f1f0e9fa5698d1daea2a94533d92ea020b154d

  • SHA256

    069818f3ba3127037ffe26196a6fb9f63471492e0c2ec5553ec160a192d812a2

  • SHA512

    c665be420e7a745b916c895751d0cd923b67dff5bb06eea96ac367b3176829b8e217c344c12276bc206abc2fd384bbe1b74d7df0fee287146d68771422c3be64

  • SSDEEP

    24576:u2G/nvxW3WieCY6dk2xGFNPYJCNAUuF23Gyxibkbl+4J:ubA3jYwVGP3yU62nsq

Malware Config

Signatures

  • DcRat 7 IoCs

    DarkCrystal(DC) is a new .NET RAT active since June 2019 capable of loading additional plugins.

  • Modifies WinLogon for persistence 2 TTPs 6 IoCs
  • DCRat payload 8 IoCs

    Detects payload of DCRat, commonly dropped by NSIS installers.

  • Executes dropped EXE 2 IoCs
  • Loads dropped DLL 2 IoCs
  • Adds Run key to start application 2 TTPs 12 IoCs
  • Drops file in System32 directory 7 IoCs
  • Drops file in Program Files directory 2 IoCs
  • Drops file in Windows directory 2 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Creates scheduled task(s) 1 TTPs 6 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

  • Suspicious behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 33 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\HEUR-Trojan-Spy.MSIL.Stealer.gen-069818f3ba31.exe
    "C:\Users\Admin\AppData\Local\Temp\HEUR-Trojan-Spy.MSIL.Stealer.gen-069818f3ba31.exe"
    1⤵
    • Suspicious use of WriteProcessMemory
    PID:1348
    • C:\Windows\SysWOW64\WScript.exe
      "C:\Windows\System32\WScript.exe" "C:\RefSessiondlldhcp\5ZImq5G8bisUIgF42b3VyU.vbe"
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:1008
      • C:\Windows\SysWOW64\cmd.exe
        cmd /c ""C:\RefSessiondlldhcp\HXUaQ2po3YKM.bat" "
        3⤵
        • Loads dropped DLL
        • Suspicious use of WriteProcessMemory
        PID:940
        • C:\RefSessiondlldhcp\RefSessiondlldhcprefbroker.exe
          "C:\RefSessiondlldhcp\RefSessiondlldhcprefbroker.exe"
          4⤵
          • DcRat
          • Modifies WinLogon for persistence
          • Executes dropped EXE
          • Adds Run key to start application
          • Drops file in System32 directory
          • Drops file in Program Files directory
          • Drops file in Windows directory
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          • Suspicious use of WriteProcessMemory
          PID:704
          • C:\Windows\system32\schtasks.exe
            "schtasks" /create /tn "dwm" /sc ONLOGON /tr "'C:\Windows\System32\MUILanguageCleanup\dwm.exe'" /rl HIGHEST /f
            5⤵
            • DcRat
            • Creates scheduled task(s)
            PID:1108
          • C:\Windows\system32\schtasks.exe
            "schtasks" /create /tn "RefSessiondlldhcprefbroker" /sc ONLOGON /tr "'C:\RefSessiondlldhcp\RefSessiondlldhcprefbroker\RefSessiondlldhcprefbroker.exe'" /rl HIGHEST /f
            5⤵
            • DcRat
            • Creates scheduled task(s)
            PID:1040
          • C:\Windows\system32\schtasks.exe
            "schtasks" /create /tn "spoolsv" /sc ONLOGON /tr "'C:\Windows\System32\azroles\spoolsv.exe'" /rl HIGHEST /f
            5⤵
            • DcRat
            • Creates scheduled task(s)
            PID:2020
          • C:\Windows\system32\schtasks.exe
            "schtasks" /create /tn "csrss" /sc ONLOGON /tr "'C:\Windows\Panther\UnattendGC\csrss.exe'" /rl HIGHEST /f
            5⤵
            • DcRat
            • Creates scheduled task(s)
            PID:1908
          • C:\Windows\system32\schtasks.exe
            "schtasks" /create /tn "RefSessiondlldhcprefbroker" /sc ONLOGON /tr "'C:\Program Files (x86)\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\RefSessiondlldhcprefbroker.exe'" /rl HIGHEST /f
            5⤵
            • DcRat
            • Creates scheduled task(s)
            PID:1952
          • C:\Windows\system32\schtasks.exe
            "schtasks" /create /tn "taskhost" /sc ONLOGON /tr "'C:\Windows\System32\rdpcore\taskhost.exe'" /rl HIGHEST /f
            5⤵
            • DcRat
            • Creates scheduled task(s)
            PID:1684
          • C:\Program Files (x86)\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\RefSessiondlldhcprefbroker.exe
            "C:\Program Files (x86)\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\RefSessiondlldhcprefbroker.exe"
            5⤵
            • Executes dropped EXE
            • Suspicious behavior: EnumeratesProcesses
            • Suspicious use of AdjustPrivilegeToken
            PID:1804

Network

MITRE ATT&CK Enterprise v6

Replay Monitor

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Downloads

  • C:\Program Files (x86)\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\RefSessiondlldhcprefbroker.exe

    Filesize

    1.1MB

    MD5

    361e744e57efd4bc271823b42f432e89

    SHA1

    9a2a63b5b045b184508c0044c5dcbe90a6f5d6ff

    SHA256

    a53b9fdd58d83816a7c3f5295cc2d22eed54e100db8bc4da5f4f26a1b055f12e

    SHA512

    3968ee19077e882e14e9b3d955c37c90d7475b45a7230ed746eb2f4f2e07b6143e008bc46a23485540642548b0d90d4dd0ac2c73eeb3c7588cf8b43ad969cfad

  • C:\Program Files (x86)\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\RefSessiondlldhcprefbroker.exe

    Filesize

    1.1MB

    MD5

    361e744e57efd4bc271823b42f432e89

    SHA1

    9a2a63b5b045b184508c0044c5dcbe90a6f5d6ff

    SHA256

    a53b9fdd58d83816a7c3f5295cc2d22eed54e100db8bc4da5f4f26a1b055f12e

    SHA512

    3968ee19077e882e14e9b3d955c37c90d7475b45a7230ed746eb2f4f2e07b6143e008bc46a23485540642548b0d90d4dd0ac2c73eeb3c7588cf8b43ad969cfad

  • C:\RefSessiondlldhcp\5ZImq5G8bisUIgF42b3VyU.vbe

    Filesize

    206B

    MD5

    ef4a52530ae724af1560718fac8ea4ce

    SHA1

    84c27d9b7cefa0dcd5437e3e1f3b114343a023fc

    SHA256

    3fb1c367a9e58fcb8ac9f2f6cf47a7f60371af030aaf3b71be6d28a555104e65

    SHA512

    8d90088149b01722d07177f12625906094d9603c21ad852798efe15ad9d2484ccd22ac541fea9b206ed09835fee0a716f7e23a8bcadceb400bb94a428a3b9d95

  • C:\RefSessiondlldhcp\HXUaQ2po3YKM.bat

    Filesize

    53B

    MD5

    3b039ddcba9d27b07e169b03c380332e

    SHA1

    e8208c0ee97a06708c3f7367f16510fa4a3449ed

    SHA256

    67154ac651824da0d440b8b9843393559dbc3b285d702c4f492be15859196e47

    SHA512

    f2d2e068b9298f205d559bb4e812bb5479fa1e4dac06780555d87ef60a931ce65e92730548d700855997c3735cbc7df02bbe41891ae0a2cad01ad10cfdd5a4a0

  • C:\RefSessiondlldhcp\RefSessiondlldhcprefbroker.exe

    Filesize

    1.1MB

    MD5

    361e744e57efd4bc271823b42f432e89

    SHA1

    9a2a63b5b045b184508c0044c5dcbe90a6f5d6ff

    SHA256

    a53b9fdd58d83816a7c3f5295cc2d22eed54e100db8bc4da5f4f26a1b055f12e

    SHA512

    3968ee19077e882e14e9b3d955c37c90d7475b45a7230ed746eb2f4f2e07b6143e008bc46a23485540642548b0d90d4dd0ac2c73eeb3c7588cf8b43ad969cfad

  • C:\RefSessiondlldhcp\RefSessiondlldhcprefbroker.exe

    Filesize

    1.1MB

    MD5

    361e744e57efd4bc271823b42f432e89

    SHA1

    9a2a63b5b045b184508c0044c5dcbe90a6f5d6ff

    SHA256

    a53b9fdd58d83816a7c3f5295cc2d22eed54e100db8bc4da5f4f26a1b055f12e

    SHA512

    3968ee19077e882e14e9b3d955c37c90d7475b45a7230ed746eb2f4f2e07b6143e008bc46a23485540642548b0d90d4dd0ac2c73eeb3c7588cf8b43ad969cfad

  • \RefSessiondlldhcp\RefSessiondlldhcprefbroker.exe

    Filesize

    1.1MB

    MD5

    361e744e57efd4bc271823b42f432e89

    SHA1

    9a2a63b5b045b184508c0044c5dcbe90a6f5d6ff

    SHA256

    a53b9fdd58d83816a7c3f5295cc2d22eed54e100db8bc4da5f4f26a1b055f12e

    SHA512

    3968ee19077e882e14e9b3d955c37c90d7475b45a7230ed746eb2f4f2e07b6143e008bc46a23485540642548b0d90d4dd0ac2c73eeb3c7588cf8b43ad969cfad

  • \RefSessiondlldhcp\RefSessiondlldhcprefbroker.exe

    Filesize

    1.1MB

    MD5

    361e744e57efd4bc271823b42f432e89

    SHA1

    9a2a63b5b045b184508c0044c5dcbe90a6f5d6ff

    SHA256

    a53b9fdd58d83816a7c3f5295cc2d22eed54e100db8bc4da5f4f26a1b055f12e

    SHA512

    3968ee19077e882e14e9b3d955c37c90d7475b45a7230ed746eb2f4f2e07b6143e008bc46a23485540642548b0d90d4dd0ac2c73eeb3c7588cf8b43ad969cfad

  • memory/704-65-0x00000000009B0000-0x0000000000ADC000-memory.dmp

    Filesize

    1.2MB

  • memory/704-63-0x0000000000000000-mapping.dmp

  • memory/940-59-0x0000000000000000-mapping.dmp

  • memory/1008-55-0x0000000000000000-mapping.dmp

  • memory/1040-67-0x0000000000000000-mapping.dmp

  • memory/1108-66-0x0000000000000000-mapping.dmp

  • memory/1348-54-0x0000000076201000-0x0000000076203000-memory.dmp

    Filesize

    8KB

  • memory/1684-71-0x0000000000000000-mapping.dmp

  • memory/1804-72-0x0000000000000000-mapping.dmp

  • memory/1804-75-0x00000000012C0000-0x00000000013EC000-memory.dmp

    Filesize

    1.2MB

  • memory/1908-69-0x0000000000000000-mapping.dmp

  • memory/1952-70-0x0000000000000000-mapping.dmp

  • memory/2020-68-0x0000000000000000-mapping.dmp