dcrat | 4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148

General

Target

4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe
Size

1.2MB
MD5

fd7254eaa1f74120831e100852a67077
SHA1

03974b230e17665e275b1f684251456ab563b0d5
SHA256

4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148
SHA512

18d77b7853a7f2788fbe27b9ba6c1bdf529379ee0cdcce580db994ff7413ddce15464481224f1174e3769b6263d576d1da5ad88510a50399b646b23acbafc82a
SSDEEP

24576:B2G/nvxW3W0nme0wCtsOkpS8BUvLlR5RevPxsJT2xdHM+4B:BbA3Huw/H08qRqvJsJTkHq

Score

10^/10

dcrat discovery infostealer persistence rat

Malware Config

Signatures

DcRat 5 IoCs

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

rat infostealer dcrat

description	ioc	pid	Process
		4060	schtasks.exe
		884	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language		4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe
		1872	schtasks.exe
		1940	schtasks.exe

Dcrat family
dcrat

Process spawned unexpected child process 4 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	1872	1456	schtasks.exe	88
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1940	1456	schtasks.exe	88
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4060	1456	schtasks.exe	88
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	884	1456	schtasks.exe	88

DCRat payload 2 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral2/files/0x0007000000023c92-10.dat	dcrat
behavioral2/memory/2984-13-0x0000000000E20000-0x0000000000F0A000-memory.dmp	dcrat

Checks computer location settings 2 TTPs 3 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-1-5-21-1045960512-3948844814-3059691613-1000\Control Panel\International\Geo\Nation	4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe
Key value queried	\REGISTRY\USER\S-1-5-21-1045960512-3948844814-3059691613-1000\Control Panel\International\Geo\Nation	WScript.exe
Key value queried	\REGISTRY\USER\S-1-5-21-1045960512-3948844814-3059691613-1000\Control Panel\International\Geo\Nation	WinsessionBrokernetIntohost.exe

Executes dropped EXE 2 IoCs

pid	Process
2984	WinsessionBrokernetIntohost.exe
4768	RuntimeBroker.exe

Adds Run key to start application 2 TTPs 4 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\taskhostw = "\"C:\\Windows\\System32\\WindowsCodecsExt\\taskhostw.exe\""	WinsessionBrokernetIntohost.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\RuntimeBroker = "\"C:\\Users\\Default User\\RuntimeBroker.exe\""	WinsessionBrokernetIntohost.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\SearchApp = "\"C:\\Windows\\SystemApps\\Microsoft.Windows.Search_cw5n1h2txyewy\\SearchApi\\SearchApp.exe\""	WinsessionBrokernetIntohost.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\StartMenuExperienceHost = "\"C:\\Windows\\SystemApps\\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\\StartUI\\StartMenuExperienceHost.exe\""	WinsessionBrokernetIntohost.exe

Drops file in System32 directory 3 IoCs

description	ioc	Process
File created	C:\Windows\System32\WindowsCodecsExt\taskhostw.exe	WinsessionBrokernetIntohost.exe
File opened for modification	C:\Windows\System32\WindowsCodecsExt\taskhostw.exe	WinsessionBrokernetIntohost.exe
File created	C:\Windows\System32\WindowsCodecsExt\ea9f0e6c9e2dcd4dfacdaf29ba21541fb815a988	WinsessionBrokernetIntohost.exe

Drops file in Windows directory 4 IoCs

description	ioc	Process
File created	C:\Windows\SystemApps\Microsoft.Windows.Search_cw5n1h2txyewy\SearchApi\SearchApp.exe	WinsessionBrokernetIntohost.exe
File created	C:\Windows\SystemApps\Microsoft.Windows.Search_cw5n1h2txyewy\SearchApi\38384e6a620884a6b69bcc56f80d556f9200171c	WinsessionBrokernetIntohost.exe
File created	C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartUI\StartMenuExperienceHost.exe	WinsessionBrokernetIntohost.exe
File created	C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartUI\55b276f4edf653fe07efe8f1ecc32d3d195abd16	WinsessionBrokernetIntohost.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	4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	WScript.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe

Modifies registry class 2 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-1045960512-3948844814-3059691613-1000_Classes\Local Settings	4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe
Key created	\REGISTRY\USER\S-1-5-21-1045960512-3948844814-3059691613-1000_Classes\Local Settings	WinsessionBrokernetIntohost.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 4 IoCs

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

persistence execution

Scheduled Task

T1053.005

pid	Process
1872	schtasks.exe
1940	schtasks.exe
4060	schtasks.exe
884	schtasks.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
2984	WinsessionBrokernetIntohost.exe
4768	RuntimeBroker.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2984	WinsessionBrokernetIntohost.exe
Token: SeDebugPrivilege	4768	RuntimeBroker.exe

Suspicious use of WriteProcessMemory 14 IoCs

description	pid	Process	procid_target
PID 1520 wrote to memory of 3148	1520	4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe	83
PID 1520 wrote to memory of 3148	1520	4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe	83
PID 1520 wrote to memory of 3148	1520	4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe	83
PID 3148 wrote to memory of 1328	3148	WScript.exe	92
PID 3148 wrote to memory of 1328	3148	WScript.exe	92
PID 3148 wrote to memory of 1328	3148	WScript.exe	92
PID 1328 wrote to memory of 2984	1328	cmd.exe	94
PID 1328 wrote to memory of 2984	1328	cmd.exe	94
PID 2984 wrote to memory of 3112	2984	WinsessionBrokernetIntohost.exe	99
PID 2984 wrote to memory of 3112	2984	WinsessionBrokernetIntohost.exe	99
PID 3112 wrote to memory of 1000	3112	cmd.exe	101
PID 3112 wrote to memory of 1000	3112	cmd.exe	101
PID 3112 wrote to memory of 4768	3112	cmd.exe	107
PID 3112 wrote to memory of 4768	3112	cmd.exe	107

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\4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe
"C:\Users\Admin\AppData\Local\Temp\4f397836d46f499ed2e76b1d3df48a3327732dcc5c5f88b566add627932ad148.exe"
1⤵
- DcRat
- Checks computer location settings
- System Location Discovery: System Language Discovery
- Modifies registry class
- Suspicious use of WriteProcessMemory
PID:1520
- C:\Windows\SysWOW64\WScript.exe
  "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\ufqa67DL2gtzgC.vbe"
  2⤵
  - Checks computer location settings
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:3148
- - C:\Windows\SysWOW64\cmd.exe
    C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\vxdOo.bat" "
    3⤵
    - System Location Discovery: System Language Discovery
    - Suspicious use of WriteProcessMemory
    PID:1328
  - - C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\WinsessionBrokernetIntohost.exe
      "C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\WinsessionBrokernetIntohost.exe"
      4⤵
      Checks computer location settings
      Executes dropped EXE
      Adds Run key to start application
      Drops file in System32 directory
      Drops file in Windows directory
      Modifies registry class
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      Suspicious use of WriteProcessMemory
      PID:2984
    - - C:\Windows\System32\cmd.exe
        
        "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\va6vjReHIA.bat"
        5⤵
        Suspicious use of WriteProcessMemory
        
        PID:3112
      - C:\Windows\system32\w32tm.exe
        
        w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
        6⤵
        
        PID:1000
      - C:\Users\Default User\RuntimeBroker.exe
        
        "C:\Users\Default User\RuntimeBroker.exe"
        6⤵
        Executes dropped EXE
        Suspicious behavior: EnumeratesProcesses
        Suspicious use of AdjustPrivilegeToken
        
        PID:4768

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "taskhostw" /sc ONLOGON /tr "'C:\Windows\System32\WindowsCodecsExt\taskhostw.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1872

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "RuntimeBroker" /sc ONLOGON /tr "'C:\Users\Default User\RuntimeBroker.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1940

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "SearchApp" /sc ONLOGON /tr "'C:\Windows\SystemApps\Microsoft.Windows.Search_cw5n1h2txyewy\SearchApi\SearchApp.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4060

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "StartMenuExperienceHost" /sc ONLOGON /tr "'C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartUI\StartMenuExperienceHost.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:884

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

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

2

T1012

System Information Discovery

2

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\va6vjReHIA.bat

Filesize
203B

MD5
43de555bdb78110b34b12d423b1bd7ad

SHA1
0cb6bad7f7b32ec179f4ce4f1bb8d1e1dacfb491

SHA256
f3e5fc2851ae4abfcbb2522e5f3cc8d61d77612b0b52751a3f6aa14d0dc00a61

SHA512
87ad1dd6884ed2c8c48907726e872d9897e6a3d0d27583371b3ab38e0ce7fc823a030c3bb12a3ae304fb1622e7548f7e44cd6cdce999bb0bf3b677f93a6aa1a4

Download Submit
C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\WinsessionBrokernetIntohost.exe

Filesize
910KB

MD5
3c0e66c07059d17b9dec156ae1f99fcf

SHA1
a9cf63368c43a839590f55a4896d503909d4ea76

SHA256
bd10ea4eeb2a7f1e9b3157ce51752336fe3d6dc56fb49bdc736bbe0ea34f5936

SHA512
4a7d7555e6cf982c62fe7185f7b147c959a82b3be5e33aeec7bc9f22ab8adcdf4cf9ca10a2a7be50a7f98c19402f8bde9fff22ff8de3e3727a8a35604767ab39

Download Submit
C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\ufqa67DL2gtzgC.vbe

Filesize
208B

MD5
79ec3118b469d48b8b3b6a1c0b330fb5

SHA1
9ef874c6a1ca3af5e07e83260dee0dc6ff7e3816

SHA256
b3bbe75c2eed62015193612b19c38eabb1c7a7b51797ad9ffa26b1eb7485839f

SHA512
0d085322c07d4553cbe7303a1a88ec329845a25ba07efe83989f912ab4e311f7ef891c2c071e87adb2de2b8b2c4e4ef5a2673b02ad8b45444e6663ead1fd0580

Download Submit
C:\Users\Admin\AppData\Roaming\WinsessionBrokernet\vxdOo.bat

Filesize
63B

MD5
ea5bc8528b06faf92eaa4f0d6194365b

SHA1
734509caf332eeffcdfea6d079b45653876e221d

SHA256
e1d8b03b08fd259e5a9cda84dc3f646bd68701ae82586e48072b62107dfb0f7a

SHA512
11cc2fd1bd98468908a197944fbd133c23899284fb745159b140d9e1f477d8c96a03c167a229814089fdc31ceed18d32992f05dd96369cbed290b3004d298edb

Download Submit
memory/2984-12-0x00007FFC7AF63000-0x00007FFC7AF65000-memory.dmp

Filesize
8KB

Download
memory/2984-13-0x0000000000E20000-0x0000000000F0A000-memory.dmp

Filesize
936KB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads