Analysis

  • max time kernel
    48s
  • max time network
    52s
  • platform
    windows7_x64
  • resource
    win7-20220901-en
  • resource tags

    arch:x64arch:x86image:win7-20220901-enlocale:en-usos:windows7-x64system
  • submitted
    31-01-2023 21:08

General

  • Target

    8w.exe

  • Size

    952KB

  • MD5

    573241336c4b94a72fbce6aaa484a30e

  • SHA1

    6324cd79e099023ec6b9e677f694340ec47357b7

  • SHA256

    2ce7891884274f9749df0faf46bca81cb0bb8e120ef5367053689c7438ea54dc

  • SHA512

    95718232e1fcbc8ad405a83f00031219c18a29dacb76780dabdb6b97984c02518620599384a6683ebd9f0333a14e3ea98bdaa36779021600e5ccf63e8cbe803c

  • SSDEEP

    24576:u+O7F9smBDJwWmIezBLwsHuWbxR4AK5ZJXX:p8/KfRTK

Malware Config

Signatures

  • DcRat

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

  • Modifies WinLogon for persistence 2 TTPs 8 IoCs
  • Process spawned unexpected child process 8 IoCs

    This typically indicates the parent process was compromised via an exploit or macro.

  • UAC bypass 3 TTPs 6 IoCs
  • DCRat payload 4 IoCs

    Detects payload of DCRat, commonly dropped by NSIS installers.

  • Executes dropped EXE 1 IoCs
  • Adds Run key to start application 2 TTPs 16 IoCs
  • Checks whether UAC is enabled 1 TTPs 4 IoCs
  • Drops file in System32 directory 30 IoCs
  • Drops file in Program Files directory 6 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 8 IoCs

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

  • Suspicious behavior: EnumeratesProcesses 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 3 IoCs
  • System policy modification 1 TTPs 6 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\8w.exe
    "C:\Users\Admin\AppData\Local\Temp\8w.exe"
    1⤵
    • Modifies WinLogon for persistence
    • UAC bypass
    • Adds Run key to start application
    • Checks whether UAC is enabled
    • Drops file in System32 directory
    • Drops file in Program Files directory
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    • System policy modification
    PID:860
    • C:\Windows\System32\NlsLexicons0026\csrss.exe
      "C:\Windows\System32\NlsLexicons0026\csrss.exe"
      2⤵
      • UAC bypass
      • Executes dropped EXE
      • Checks whether UAC is enabled
      • Suspicious use of AdjustPrivilegeToken
      • System policy modification
      PID:1008
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "smss" /sc ONLOGON /tr "'C:\Windows\System32\msieftp\smss.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:1784
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "smss" /sc ONLOGON /tr "'C:\Windows\System32\wshqos\smss.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:1096
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "spoolsv" /sc ONLOGON /tr "'C:\Windows\System32\usercpl\spoolsv.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:1512
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Windows\System32\NlsLexicons0026\csrss.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:988
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "WMIADAP" /sc ONLOGON /tr "'C:\Recovery\31001cc2-2a3d-11ed-9244-9c23e66b04e4\WMIADAP.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:2016
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "explorer" /sc ONLOGON /tr "'C:\Program Files\Windows Portable Devices\explorer.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:1968
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "wininit" /sc ONLOGON /tr "'C:\Windows\System32\vcomp140\wininit.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:1492
  • C:\Windows\system32\schtasks.exe
    schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Windows\System32\odbccr32\csrss.exe'" /rl HIGHEST /f
    1⤵
    • Process spawned unexpected child process
    • Creates scheduled task(s)
    PID:344

Network

MITRE ATT&CK Matrix ATT&CK v6

Execution

Scheduled Task

1
T1053

Persistence

Winlogon Helper DLL

1
T1004

Registry Run Keys / Startup Folder

1
T1060

Scheduled Task

1
T1053

Privilege Escalation

Bypass User Account Control

1
T1088

Scheduled Task

1
T1053

Defense Evasion

Modify Registry

4
T1112

Bypass User Account Control

1
T1088

Disabling Security Tools

1
T1089

Discovery

System Information Discovery

2
T1082

Replay Monitor

Loading Replay Monitor...

Downloads

  • C:\Windows\System32\NlsLexicons0026\csrss.exe
    Filesize

    952KB

    MD5

    9e3e7b6bc99fd1f3ff2ebca8724997d9

    SHA1

    3e023260dec0fdac83841124853d69e1932cbfab

    SHA256

    18959f001e44d6dfb67a0d122f61845fadb732ee18de48efc278b54878e89445

    SHA512

    cbf6789f43e92acb85721fac0095c2013868c7c34ab331977a1d77c4b78bb6de8038fd3cb35c3657fd32a9662f8de61f6b88bd645e01bcd6a48f4cb46618a53a

  • C:\Windows\System32\NlsLexicons0026\csrss.exe
    Filesize

    952KB

    MD5

    9e3e7b6bc99fd1f3ff2ebca8724997d9

    SHA1

    3e023260dec0fdac83841124853d69e1932cbfab

    SHA256

    18959f001e44d6dfb67a0d122f61845fadb732ee18de48efc278b54878e89445

    SHA512

    cbf6789f43e92acb85721fac0095c2013868c7c34ab331977a1d77c4b78bb6de8038fd3cb35c3657fd32a9662f8de61f6b88bd645e01bcd6a48f4cb46618a53a

  • memory/860-60-0x00000000004C0000-0x00000000004C8000-memory.dmp
    Filesize

    32KB

  • memory/860-57-0x0000000000460000-0x000000000046A000-memory.dmp
    Filesize

    40KB

  • memory/860-58-0x00000000004B0000-0x00000000004BC000-memory.dmp
    Filesize

    48KB

  • memory/860-59-0x0000000000480000-0x000000000048A000-memory.dmp
    Filesize

    40KB

  • memory/860-54-0x0000000000C10000-0x0000000000D04000-memory.dmp
    Filesize

    976KB

  • memory/860-61-0x00000000004D0000-0x00000000004DA000-memory.dmp
    Filesize

    40KB

  • memory/860-62-0x00000000004E0000-0x00000000004EC000-memory.dmp
    Filesize

    48KB

  • memory/860-63-0x0000000000940000-0x000000000094C000-memory.dmp
    Filesize

    48KB

  • memory/860-56-0x0000000000450000-0x0000000000460000-memory.dmp
    Filesize

    64KB

  • memory/860-55-0x00000000003C0000-0x00000000003D0000-memory.dmp
    Filesize

    64KB

  • memory/1008-64-0x0000000000000000-mapping.dmp
  • memory/1008-67-0x0000000000020000-0x0000000000114000-memory.dmp
    Filesize

    976KB