dcrat | d9cbcae95ae824014b6d2fd6d3269b00b09ab84ed44b45b21c0b1842e7cdc132

General

Target

DCRatBuild.exe
Size

1.1MB
MD5

7ef93a29c05d412dd2dc432e1aac54a9
SHA1

776cc5c36f370a7e1fa840a21c13f2278723409e
SHA256

d9cbcae95ae824014b6d2fd6d3269b00b09ab84ed44b45b21c0b1842e7cdc132
SHA512

26e00619e47a130fb768b91074915c8a69f8690ac12465f21c1bd7e69f94ae6db9a238ff3c510a719cf1a318a07c80a543212c200b2b2152934a1ad154d13ab6
SSDEEP

12288:URZ+IoG/n9IQxW3OBseUUT+tcYbv+RK+UfXST5/rKMyFckcb8M41AT0z/GAFPz3m:u2G/nvxW3WieC7STuMMATKPTVgxr4q

Score

10^/10

dcrat discovery infostealer persistence rat

Malware Config

Signatures

DcRat 16 IoCs

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

rat infostealer dcrat

description	ioc	pid	Process
		1836	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language		DCRatBuild.exe
		3004	schtasks.exe
		2908	schtasks.exe
		3024	schtasks.exe
		2380	schtasks.exe
		1444	schtasks.exe
		1460	schtasks.exe
		1500	schtasks.exe
		1692	schtasks.exe
		2832	schtasks.exe
		2972	schtasks.exe
		2820	schtasks.exe
		2444	schtasks.exe
		2516	schtasks.exe
		1040	schtasks.exe

Dcrat family
dcrat

Modifies WinLogon for persistence 2 TTPs 5 IoCs

persistence

Winlogon Helper DLL

T1547.004

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Users\\Default\\Application Data\\cmd.exe\", \"C:\\MSOCache\\All Users\\{90140000-001B-0409-0000-0000000FF1CE}-C\\dllhost.exe\", \"C:\\PortproviderRuntime\\csrss.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Users\\Default\\Application Data\\cmd.exe\", \"C:\\MSOCache\\All Users\\{90140000-001B-0409-0000-0000000FF1CE}-C\\dllhost.exe\", \"C:\\PortproviderRuntime\\csrss.exe\", \"C:\\MSOCache\\All Users\\spoolsv.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Users\\Default\\Application Data\\cmd.exe\", \"C:\\MSOCache\\All Users\\{90140000-001B-0409-0000-0000000FF1CE}-C\\dllhost.exe\", \"C:\\PortproviderRuntime\\csrss.exe\", \"C:\\MSOCache\\All Users\\spoolsv.exe\", \"C:\\Program Files\\7-Zip\\Lang\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Users\\Default\\Application Data\\cmd.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Users\\Default\\Application Data\\cmd.exe\", \"C:\\MSOCache\\All Users\\{90140000-001B-0409-0000-0000000FF1CE}-C\\dllhost.exe\""	Bridgewebsvc.exe

Process spawned unexpected child process 15 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	2832	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2972	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2820	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2516	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2444	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2380	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	3004	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1692	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1040	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1444	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2908	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1460	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	3024	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1500	2480	schtasks.exe	34
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1836	2480	schtasks.exe	34

DCRat payload 3 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral1/files/0x0008000000016cf0-9.dat	dcrat
behavioral1/memory/2168-13-0x0000000000B70000-0x0000000000C46000-memory.dmp	dcrat
behavioral1/memory/1324-30-0x00000000010C0000-0x0000000001196000-memory.dmp	dcrat

Executes dropped EXE 2 IoCs

pid	Process
2168	Bridgewebsvc.exe
1324	cmd.exe

Loads dropped DLL 2 IoCs

pid	Process
2024	cmd.exe
2024	cmd.exe

Adds Run key to start application 2 TTPs 10 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Program Files\\7-Zip\\Lang\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\cmd = "\"C:\\Users\\Default\\Application Data\\cmd.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\PortproviderRuntime\\csrss.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\PortproviderRuntime\\csrss.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\MSOCache\\All Users\\spoolsv.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Program Files\\7-Zip\\Lang\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\cmd = "\"C:\\Users\\Default\\Application Data\\cmd.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\MSOCache\\All Users\\{90140000-001B-0409-0000-0000000FF1CE}-C\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\MSOCache\\All Users\\{90140000-001B-0409-0000-0000000FF1CE}-C\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\MSOCache\\All Users\\spoolsv.exe\""	Bridgewebsvc.exe

Drops file in Program Files directory 2 IoCs

description	ioc	Process
File created	C:\Program Files\7-Zip\Lang\5940a34987c991	Bridgewebsvc.exe
File created	C:\Program Files\7-Zip\Lang\dllhost.exe	Bridgewebsvc.exe

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

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 3 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	DCRatBuild.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	WScript.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 15 IoCs

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

persistence execution

Scheduled Task

T1053.005

pid	Process
2832	schtasks.exe
2516	schtasks.exe
3024	schtasks.exe
1500	schtasks.exe
1444	schtasks.exe
2908	schtasks.exe
1460	schtasks.exe
1836	schtasks.exe
2972	schtasks.exe
2444	schtasks.exe
3004	schtasks.exe
1692	schtasks.exe
1040	schtasks.exe
2820	schtasks.exe
2380	schtasks.exe

Suspicious behavior: EnumeratesProcesses 4 IoCs

pid	Process
2168	Bridgewebsvc.exe
2168	Bridgewebsvc.exe
2168	Bridgewebsvc.exe
1324	cmd.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2168	Bridgewebsvc.exe
Token: SeDebugPrivilege	1324	cmd.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 1688 wrote to memory of 2156	1688	DCRatBuild.exe	30
PID 1688 wrote to memory of 2156	1688	DCRatBuild.exe	30
PID 1688 wrote to memory of 2156	1688	DCRatBuild.exe	30
PID 1688 wrote to memory of 2156	1688	DCRatBuild.exe	30
PID 2156 wrote to memory of 2024	2156	WScript.exe	31
PID 2156 wrote to memory of 2024	2156	WScript.exe	31
PID 2156 wrote to memory of 2024	2156	WScript.exe	31
PID 2156 wrote to memory of 2024	2156	WScript.exe	31
PID 2024 wrote to memory of 2168	2024	cmd.exe	33
PID 2024 wrote to memory of 2168	2024	cmd.exe	33
PID 2024 wrote to memory of 2168	2024	cmd.exe	33
PID 2024 wrote to memory of 2168	2024	cmd.exe	33
PID 2168 wrote to memory of 1324	2168	Bridgewebsvc.exe	50
PID 2168 wrote to memory of 1324	2168	Bridgewebsvc.exe	50
PID 2168 wrote to memory of 1324	2168	Bridgewebsvc.exe	50

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.
persistence

Query Registry
T1012

C:\Users\Admin\AppData\Local\Temp\DCRatBuild.exe
"C:\Users\Admin\AppData\Local\Temp\DCRatBuild.exe"
1⤵
- DcRat
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:1688
- C:\Windows\SysWOW64\WScript.exe
  "C:\Windows\System32\WScript.exe" "C:\PortproviderRuntime\2jiE6dDNxF2hUpVE5Z.vbe"
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:2156
- - C:\Windows\SysWOW64\cmd.exe
    cmd /c ""C:\PortproviderRuntime\OI2YygSphQCiiCNA7ofzvo.bat" "
    3⤵
    - Loads dropped DLL
    - System Location Discovery: System Language Discovery
    - Suspicious use of WriteProcessMemory
    PID:2024
  - - C:\PortproviderRuntime\Bridgewebsvc.exe
      "C:\PortproviderRuntime\Bridgewebsvc.exe"
      4⤵
      Modifies WinLogon for persistence
      Executes dropped EXE
      Adds Run key to start application
      Drops file in Program Files directory
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      Suspicious use of WriteProcessMemory
      PID:2168
    - - C:\Users\Default\Application Data\cmd.exe
        
        "C:\Users\Default\Application Data\cmd.exe"
        5⤵
        Executes dropped EXE
        Suspicious behavior: EnumeratesProcesses
        Suspicious use of AdjustPrivilegeToken
        
        PID:1324

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "cmdc" /sc MINUTE /mo 10 /tr "'C:\Users\Default\Application Data\cmd.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2832

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "cmd" /sc ONLOGON /tr "'C:\Users\Default\Application Data\cmd.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2972

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "cmdc" /sc MINUTE /mo 7 /tr "'C:\Users\Default\Application Data\cmd.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2820

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhostd" /sc MINUTE /mo 12 /tr "'C:\MSOCache\All Users\{90140000-001B-0409-0000-0000000FF1CE}-C\dllhost.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2516

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhost" /sc ONLOGON /tr "'C:\MSOCache\All Users\{90140000-001B-0409-0000-0000000FF1CE}-C\dllhost.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2444

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhostd" /sc MINUTE /mo 6 /tr "'C:\MSOCache\All Users\{90140000-001B-0409-0000-0000000FF1CE}-C\dllhost.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2380

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 8 /tr "'C:\PortproviderRuntime\csrss.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:3004

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\PortproviderRuntime\csrss.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1692

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 5 /tr "'C:\PortproviderRuntime\csrss.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1040

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "spoolsvs" /sc MINUTE /mo 14 /tr "'C:\MSOCache\All Users\spoolsv.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1444

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "spoolsv" /sc ONLOGON /tr "'C:\MSOCache\All Users\spoolsv.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2908

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "spoolsvs" /sc MINUTE /mo 9 /tr "'C:\MSOCache\All Users\spoolsv.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1460

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhostd" /sc MINUTE /mo 14 /tr "'C:\Program Files\7-Zip\Lang\dllhost.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:3024

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhost" /sc ONLOGON /tr "'C:\Program Files\7-Zip\Lang\dllhost.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1500

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhostd" /sc MINUTE /mo 8 /tr "'C:\Program Files\7-Zip\Lang\dllhost.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1836

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Boot or Logon Autostart Execution

2

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Winlogon Helper DLL

1

T1547.004

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Boot or Logon Autostart Execution

2

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Winlogon Helper DLL

1

T1547.004

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Modify Registry

2

T1112

Credential Access

Discovery

Query Registry

1

T1012

System Information Discovery

1

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\PortproviderRuntime\2jiE6dDNxF2hUpVE5Z.vbe

Filesize
218B

MD5
413767cf51f36f7f50d9430d73ea0bb1

SHA1
4469733bce94a114c836ea3591dccb3e689782c7

SHA256
2e118668b3c63457b924aafd6b402e105477030d6157e3d66ba8ba7acad58dcf

SHA512
3c12a46412227f57f8aa815b0b7820ca54eb3fa7a033ea7baa7efad7526755db7998d843a6790880efa87b841e9c6085b793930ae865c2694c8385e5937ee900

Download Submit
C:\PortproviderRuntime\OI2YygSphQCiiCNA7ofzvo.bat

Filesize
41B

MD5
863d81db66a0a5864890665ea50c23c5

SHA1
f5a584f4ee5e390b667eaa5e5d9332251388fa7e

SHA256
d4fa2e3203a21efd9f46fd9ea5fcedbabe13bd9a2bc93d0169070507380bbf9b

SHA512
ecb8ff338e0febcfe8965516a58dcdcd63420592467ce1c281f7ccacf7a2ca02bd7a73d52208e98edec3e73ea69477f3ccaa4ddf4b0608e5598a92e110e5d3b0

Download Submit
\PortproviderRuntime\Bridgewebsvc.exe

Filesize
828KB

MD5
fddea23e803e9e5de212e4c0475c8f93

SHA1
c4426bf36ce54917155da2bfbec1508c5a799664

SHA256
f014b4dd1600fb5ecd92de55165573415c2d7ee184a4f70f2f975ee7909150f6

SHA512
05459fc75998ee306e8de7e544aaf744e5c6e1930dcb7e02b94a566a7ad6e874a9fe50a78a1da50b4e7110282e49353f8ced586117d772b600b84d09ee070591

Download Submit
memory/1324-30-0x00000000010C0000-0x0000000001196000-memory.dmp

Filesize
856KB

Download
memory/2168-13-0x0000000000B70000-0x0000000000C46000-memory.dmp

Filesize
856KB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads