dcrat | 8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e6176f54daeaff7e9654fc

General

Target
8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Size 1.5MB
Sample220310-x9jpbsdffp
SHA256 8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e6176f54daeaff7e9654fc
MD5 cdd2e8326dc322c3848da68ec5875271
SHA1 6aaf552da3a9d164bfb5098d388afe9650f92fb4
SHA512 67b01f89e2aafde229a53bc2a1fa36dc5818b82bf4837910e00c6e4199b79f6ef686607d5d834ece4815a59ae0543aee3a9ed4d19f3154d29dcb1cef81919ce9
MD5 SHA1 SHA512

Score

10^/10

dcrat infostealer persistence rat spyware stealer

Malware Config

Signatures

DcRat 7 IoCs

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

rat infostealer dcrat

description	ioc	pid	Process
		400	schtasks.exe
File created	C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost\StartMenuExperienceHost.exe		8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\""		8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\StartMenuExperienceHost = "\"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\""		8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\StartMenuExperienceHost = "\"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\""		8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
		4560	schtasks.exe
		3964	schtasks.exe

Modifies WinLogon for persistence 2 TTPs 3 IoCs

persistence

Winlogon Helper DLL

T1004

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\", \"C:\\Windows\\System32\\bcd\\RuntimeBroker.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\", \"C:\\Windows\\System32\\bcd\\RuntimeBroker.exe\", \"C:\\Windows\\System32\\ws2_32\\spoolsv.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe

Process spawned unexpected child process 3 IoCs

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

description	pid	pid_target	Process	procid_target
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4560	2556	schtasks.exe	80
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	3964	2556	schtasks.exe	80
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	400	2556	schtasks.exe	80

Executes dropped EXE 1 IoCs

pid	Process
1152	RuntimeBroker.exe

Checks computer location settings 2 TTPs 1 IoCs

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

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000\Control Panel\International\Geo\Nation	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe

Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
spyware stealer

Data from Local System
T1005

Credentials in Files
T1081
Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
spyware

Data from Local System
T1005

Credentials in Files
T1081

Adds Run key to start application 2 TTPs 6 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\RuntimeBroker = "\"C:\\Windows\\System32\\bcd\\RuntimeBroker.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\Windows\\System32\\ws2_32\\spoolsv.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\Windows\\System32\\ws2_32\\spoolsv.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\StartMenuExperienceHost = "\"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\StartMenuExperienceHost = "\"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartMenuExperienceHost\\StartMenuExperienceHost.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\RuntimeBroker = "\"C:\\Windows\\System32\\bcd\\RuntimeBroker.exe\""	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe

Drops file in System32 directory 4 IoCs

description	ioc	Process
File created	C:\Windows\SysWOW64\bcd\9e8d7a4ca61bd9	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
File created	C:\Windows\SysWOW64\ws2_32\spoolsv.exe	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
File created	C:\Windows\SysWOW64\ws2_32\f3b6ecef712a24	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
File created	C:\Windows\SysWOW64\bcd\RuntimeBroker.exe	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe

Suspicious use of NtSetInformationThreadHideFromDebugger 16 IoCs

pid	Process
1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe

Drops file in Windows directory 3 IoCs

description	ioc	Process
File created	C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost\55b276f4edf653	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
File created	C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost\StartMenuExperienceHost.exe	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
File opened for modification	C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost\StartMenuExperienceHost.exe	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082

Creates scheduled task(s) 1 TTPs 3 IoCs

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

persistence

Scheduled Task

T1053

pid	Process
4560	schtasks.exe
3964	schtasks.exe
400	schtasks.exe

Modifies registry class 1 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000_Classes\Local Settings	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe

Suspicious behavior: EnumeratesProcesses 16 IoCs

pid	Process
1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe

Suspicious behavior: GetForegroundWindowSpam 1 IoCs

pid	Process
1152	RuntimeBroker.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
Token: SeDebugPrivilege	1152	RuntimeBroker.exe

Suspicious use of SetWindowsHookEx 3 IoCs

pid	Process
1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
1152	RuntimeBroker.exe
1152	RuntimeBroker.exe

Suspicious use of WriteProcessMemory 11 IoCs

description	pid	Process	procid_target
PID 1512 wrote to memory of 4720	1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe	84
PID 1512 wrote to memory of 4720	1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe	84
PID 1512 wrote to memory of 4720	1512	8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe	84
PID 4720 wrote to memory of 4608	4720	cmd.exe	86
PID 4720 wrote to memory of 4608	4720	cmd.exe	86
PID 4720 wrote to memory of 4608	4720	cmd.exe	86
PID 4608 wrote to memory of 552	4608	w32tm.exe	87
PID 4608 wrote to memory of 552	4608	w32tm.exe	87
PID 4720 wrote to memory of 1152	4720	cmd.exe	88
PID 4720 wrote to memory of 1152	4720	cmd.exe	88
PID 4720 wrote to memory of 1152	4720	cmd.exe	88

C:\Users\Admin\AppData\Local\Temp\8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe
"C:\Users\Admin\AppData\Local\Temp\8f7bab9df8b75b06db3d3386c8fea2e31c3c829793e61.exe"
1⤵
- DcRat
- Modifies WinLogon for persistence
- Checks computer location settings
- Adds Run key to start application
- Drops file in System32 directory
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Drops file in Windows directory
- Modifies registry class
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:1512
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\B9rGlxAqwv.bat"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:4720
- - C:\Windows\SysWOW64\w32tm.exe
    w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:4608
  - - C:\Windows\system32\w32tm.exe
      w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
      4⤵
      PID:552
- - C:\Windows\SysWOW64\bcd\RuntimeBroker.exe
    "C:\Windows\System32\bcd\RuntimeBroker.exe"
    3⤵
    - Executes dropped EXE
    - Suspicious use of NtSetInformationThreadHideFromDebugger
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious behavior: GetForegroundWindowSpam
    - Suspicious use of AdjustPrivilegeToken
    - Suspicious use of SetWindowsHookEx
    PID:1152

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "StartMenuExperienceHost" /sc ONLOGON /tr "'C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost\StartMenuExperienceHost.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:4560

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "RuntimeBroker" /sc ONLOGON /tr "'C:\Windows\System32\bcd\RuntimeBroker.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:3964

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "spoolsv" /sc ONLOGON /tr "'C:\Windows\System32\ws2_32\spoolsv.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:400