Analysis
- max time kernel
571s - max time network
595s - platform
windows10-2004_x64 - resource
win10v2004-20240611-en - resource tags
- submitted
19/06/2024, 14:54
General
- Target DCRatBuild.exe
- Size 1.5MB
- Sample240619-r94fvasdmb
- SHA256 7b612f59430f89b4a130c19c3f59e036e93cd21b8b8dd9049f453ad39aefb516
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 2 IoCs
- Process spawned unexpected child process 6 IoCs
This typically indicates the parent process was compromised via an exploit or macro.
- DCRat payload 2 IoCs
Detects payload of DCRat, commonly dropped by NSIS installers.
- Checks computer location settings 2 TTPs 3 IoCs
Looks up country code configured in the registry, likely geofence.
- Executes dropped EXE 4 IoCs
- Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
- Adds Run key to start application 2 TTPs 4 IoCs
- Drops file in Program Files directory 5 IoCs
- Drops file in Windows directory 1 IoCs
- Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).
- Modifies registry class 2 IoCs
- Scheduled Task/Job: Scheduled Task 1 TTPs 6 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
- Suspicious behavior: EnumeratesProcesses 14 IoCs
- Suspicious behavior: GetForegroundWindowSpam 1 IoCs
- Suspicious use of AdjustPrivilegeToken 4 IoCs
- Suspicious use of WriteProcessMemory 14 IoCs
- Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
Processes
-
C:\Users\Admin\AppData\Local\Temp\DCRatBuild.exe"C:\Users\Admin\AppData\Local\Temp\DCRatBuild.exe"1⤵
- Checks computer location settings
- Modifies registry class
- Suspicious use of WriteProcessMemory
-
C:\Windows\SysWOW64\WScript.exe"C:\Windows\System32\WScript.exe" "C:\blockComagentCommon\XXy2W.vbe"2⤵
- Checks computer location settings
- Suspicious use of WriteProcessMemory
-
C:\Windows\SysWOW64\cmd.exeC:\Windows\system32\cmd.exe /c ""C:\blockComagentCommon\0xQrS65tkQIWur3PmtNOw.bat" "3⤵
- Suspicious use of WriteProcessMemory
-
C:\blockComagentCommon\bridgehypercom.exe"C:\blockComagentCommon\bridgehypercom.exe"4⤵
- Modifies WinLogon for persistence
- Checks computer location settings
- Executes dropped EXE
- Adds Run key to start application
- Drops file in Program Files directory
- Drops file in Windows directory
- Modifies registry class
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
-
C:\Windows\System32\cmd.exe"C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\f3ob5ZjYhN.bat"5⤵
- Suspicious use of WriteProcessMemory
-
C:\Windows\system32\w32tm.exew32tm /stripchart /computer:localhost /period:5 /dataonly /samples:26⤵
-
-
C:\Program Files\Google\Chrome\Application\110.0.5481.104\WidevineCdm\OfficeClickToRun.exe"C:\Program Files\Google\Chrome\Application\110.0.5481.104\WidevineCdm\OfficeClickToRun.exe"6⤵
- Executes dropped EXE
- Suspicious behavior: EnumeratesProcesses
- Suspicious behavior: GetForegroundWindowSpam
- Suspicious use of AdjustPrivilegeToken
-
-
-
-
-
-
C:\Windows\system32\schtasks.exeschtasks.exe /create /tn "OfficeClickToRunO" /sc MINUTE /mo 8 /tr "'C:\Program Files\Google\Chrome\Application\110.0.5481.104\WidevineCdm\OfficeClickToRun.exe'" /f1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
-
C:\Windows\system32\schtasks.exeschtasks.exe /create /tn "OfficeClickToRun" /sc ONLOGON /tr "'C:\Program Files\Google\Chrome\Application\110.0.5481.104\WidevineCdm\OfficeClickToRun.exe'" /rl HIGHEST /f1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
-
C:\Windows\system32\schtasks.exeschtasks.exe /create /tn "OfficeClickToRunO" /sc MINUTE /mo 13 /tr "'C:\Program Files\Google\Chrome\Application\110.0.5481.104\WidevineCdm\OfficeClickToRun.exe'" /rl HIGHEST /f1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
-
C:\Windows\system32\schtasks.exeschtasks.exe /create /tn "OfficeClickToRunO" /sc MINUTE /mo 7 /tr "'C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe'" /f1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
-
C:\Windows\system32\schtasks.exeschtasks.exe /create /tn "OfficeClickToRun" /sc ONLOGON /tr "'C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe'" /rl HIGHEST /f1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
-
C:\Windows\system32\schtasks.exeschtasks.exe /create /tn "OfficeClickToRunO" /sc MINUTE /mo 5 /tr "'C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe'" /rl HIGHEST /f1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
-
C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe"C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe"1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
-
C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe"C:\Program Files\Windows Defender\en-US\OfficeClickToRun.exe"1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
Network
MITRE ATT&CK Enterprise v15
Persistence
Boot or Logon Autostart Execution
2Registry Run Keys / Startup Folder
1Winlogon Helper DLL
1Scheduled Task/Job
1Scheduled Task
1Replay Monitor
Loading Replay Monitor...
Downloads
OfficeClickToRun.exe.log
f3ob5ZjYhN.bat
0xQrS65tkQIWur3PmtNOw.bat
XXy2W.vbe
bridgehypercom.exe
memory/1832-12-0x00007FFA4F263000-0x00007FFA4F265000-memory.dmp
memory/1832-13-0x0000000000960000-0x0000000000A92000-memory.dmp
memory/1832-14-0x0000000002B70000-0x0000000002B8C000-memory.dmp
memory/1832-15-0x000000001BDC0000-0x000000001BE10000-memory.dmp
memory/1832-16-0x0000000002CB0000-0x0000000002CC6000-memory.dmp
memory/1832-17-0x0000000002B90000-0x0000000002B9C000-memory.dmp