dcrat | 99b234ed5fcab5f1e2ebbc0a26fd5e94a3efa69fadb275065592ea7cba636e16

General

Target
b9a42f557b8e8d48bd5b061f8e714af9.exe
Size 1.2MB
Sample210911-lbbehsbbg8
SHA256 99b234ed5fcab5f1e2ebbc0a26fd5e94a3efa69fadb275065592ea7cba636e16
MD5 b9a42f557b8e8d48bd5b061f8e714af9
SHA1 f591e3bb267304fb5261465552f80910306c9ec7
SHA512 fb0577b150e658d6d182b41de88da72f26af1dc33171de54832a952defae1df8f239c8f112c6e32a26341402548a2f4965b490e4d152bb593dd4c7b9d38c4b98
MD5 SHA1 SHA512

Score

10^/10

dcrat infostealer persistence rat spyware stealer

Malware Config

Signatures

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

Process spawned unexpected child process 7 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	616	1304	schtasks.exe	36
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1700	1304	schtasks.exe	36
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	788	1304	schtasks.exe	36
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1324	1304	schtasks.exe	36
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1756	1304	schtasks.exe	36
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1868	1304	schtasks.exe	36
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1148	1304	schtasks.exe	36

DCRat Payload 8 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral1/files/0x00040000000130d7-62.dat	dcrat
behavioral1/files/0x00040000000130d7-64.dat	dcrat
behavioral1/files/0x00030000000130db-71.dat	dcrat
behavioral1/files/0x00030000000130db-74.dat	dcrat
behavioral1/files/0x00030000000130db-72.dat	dcrat
behavioral1/files/0x00030000000130db-70.dat	dcrat
behavioral1/files/0x00030000000130f4-79.dat	dcrat
behavioral1/files/0x00030000000130f4-80.dat	dcrat

Downloads MZ/PE file

Executes dropped EXE 3 IoCs

pid	Process
1584	dlihost.exe
1080	savesruntimeBrokerFontwin.exe
944	explorer.exe

Loads dropped DLL 2 IoCs

pid	Process
820	cmd.exe
820	cmd.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

Adds Run key to start application 2 TTPs 7 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Windows\\System32\\jscript9diag\\dllhost.exe\""	savesruntimeBrokerFontwin.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\wininit = "\"C:\\Users\\Default\\wininit.exe\""	savesruntimeBrokerFontwin.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\explorer = "\"C:\\Program Files (x86)\\Uninstall Information\\explorer.exe\""	savesruntimeBrokerFontwin.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Idle = "\"C:\\Program Files\\VideoLAN\\VLC\\plugins\\gui\\Idle.exe\""	savesruntimeBrokerFontwin.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\cmd = "\"C:\\Windows\\SysWOW64\\Query\\cmd.exe\""	savesruntimeBrokerFontwin.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\savesruntimeBrokerFontwin = "\"C:\\savesruntimeBroker\\bB37mtqgliH1SYemgnxw\\savesruntimeBrokerFontwin.exe\""	savesruntimeBrokerFontwin.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\explorer = "\"C:\\Windows\\Professional\\explorer.exe\""	savesruntimeBrokerFontwin.exe

Drops file in System32 directory 4 IoCs

description	ioc	Process
File created	C:\Windows\SysWOW64\Query\cmd.exe	savesruntimeBrokerFontwin.exe
File created	C:\Windows\SysWOW64\Query\ebf1f9fa8afd6d1932bd65bc4cc3af89a4c8e228	savesruntimeBrokerFontwin.exe
File created	C:\Windows\System32\jscript9diag\dllhost.exe	savesruntimeBrokerFontwin.exe
File created	C:\Windows\System32\jscript9diag\5940a34987c99120d96dace90a3f93f329dcad63	savesruntimeBrokerFontwin.exe

Drops file in Program Files directory 4 IoCs

description	ioc	Process
File created	C:\Program Files (x86)\Uninstall Information\7a0fd90576e08807bde2cc57bcf9854bbce05fe3	savesruntimeBrokerFontwin.exe
File created	C:\Program Files\VideoLAN\VLC\plugins\gui\Idle.exe	savesruntimeBrokerFontwin.exe
File created	C:\Program Files\VideoLAN\VLC\plugins\gui\6ccacd8608530fba3a93e87ae2225c7032aa18c1	savesruntimeBrokerFontwin.exe
File created	C:\Program Files (x86)\Uninstall Information\explorer.exe	savesruntimeBrokerFontwin.exe

Drops file in Windows directory 2 IoCs

description	ioc	Process
File created	C:\Windows\Professional\explorer.exe	savesruntimeBrokerFontwin.exe
File created	C:\Windows\Professional\7a0fd90576e08807bde2cc57bcf9854bbce05fe3	savesruntimeBrokerFontwin.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 7 IoCs

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

persistence

Scheduled Task

T1053

pid	Process
1868	schtasks.exe
1148	schtasks.exe
616	schtasks.exe
1700	schtasks.exe
788	schtasks.exe
1324	schtasks.exe
1756	schtasks.exe

Modifies system certificate store 2 TTPs 2 IoCs

evasion spyware trojan

Install Root Certificate

T1130

Modify Registry

T1112

description	ioc	Process
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates\DAC9024F54D8F6DF94935FB1732638CA6AD77C13	b9a42f557b8e8d48bd5b061f8e714af9.exe
Set value (data)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates\DAC9024F54D8F6DF94935FB1732638CA6AD77C13\Blob = 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	b9a42f557b8e8d48bd5b061f8e714af9.exe

Suspicious behavior: EnumeratesProcesses 6 IoCs

pid	Process
1080	savesruntimeBrokerFontwin.exe
944	explorer.exe
944	explorer.exe
944	explorer.exe
944	explorer.exe
944	explorer.exe

Suspicious behavior: GetForegroundWindowSpam 1 IoCs

pid	Process
944	explorer.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	1080	savesruntimeBrokerFontwin.exe
Token: SeDebugPrivilege	944	explorer.exe

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 1840 wrote to memory of 1584	1840	b9a42f557b8e8d48bd5b061f8e714af9.exe	30
PID 1840 wrote to memory of 1584	1840	b9a42f557b8e8d48bd5b061f8e714af9.exe	30
PID 1840 wrote to memory of 1584	1840	b9a42f557b8e8d48bd5b061f8e714af9.exe	30
PID 1840 wrote to memory of 1584	1840	b9a42f557b8e8d48bd5b061f8e714af9.exe	30
PID 1584 wrote to memory of 1852	1584	dlihost.exe	32
PID 1584 wrote to memory of 1852	1584	dlihost.exe	32
PID 1584 wrote to memory of 1852	1584	dlihost.exe	32
PID 1584 wrote to memory of 1852	1584	dlihost.exe	32
PID 1852 wrote to memory of 820	1852	WScript.exe	33
PID 1852 wrote to memory of 820	1852	WScript.exe	33
PID 1852 wrote to memory of 820	1852	WScript.exe	33
PID 1852 wrote to memory of 820	1852	WScript.exe	33
PID 820 wrote to memory of 1080	820	cmd.exe	35
PID 820 wrote to memory of 1080	820	cmd.exe	35
PID 820 wrote to memory of 1080	820	cmd.exe	35
PID 820 wrote to memory of 1080	820	cmd.exe	35
PID 1080 wrote to memory of 944	1080	savesruntimeBrokerFontwin.exe	44
PID 1080 wrote to memory of 944	1080	savesruntimeBrokerFontwin.exe	44
PID 1080 wrote to memory of 944	1080	savesruntimeBrokerFontwin.exe	44

C:\Users\Admin\AppData\Local\Temp\b9a42f557b8e8d48bd5b061f8e714af9.exe
"C:\Users\Admin\AppData\Local\Temp\b9a42f557b8e8d48bd5b061f8e714af9.exe"
1⤵
- Modifies system certificate store
- Suspicious use of WriteProcessMemory
PID:1840
- C:\Users\Admin\AppData\Local\Temp\dlihost.exe
  C:\Users\Admin\AppData\Local\Temp\dlihost.exe
  2⤵
  - Executes dropped EXE
  - Suspicious use of WriteProcessMemory
  PID:1584
- - C:\Windows\SysWOW64\WScript.exe
    "C:\Windows\System32\WScript.exe" "C:\savesruntimeBroker\bB37mtqgliH1SYemgnxw.vbe"
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:1852
  - - C:\Windows\SysWOW64\cmd.exe
      cmd /c ""C:\savesruntimeBroker\IW2ru7jY87FyQpz9to.bat" "
      4⤵
      Loads dropped DLL
      Suspicious use of WriteProcessMemory
      PID:820
    - - C:\savesruntimeBroker\savesruntimeBrokerFontwin.exe
        
        "C:\savesruntimeBroker\savesruntimeBrokerFontwin.exe"
        5⤵
        Executes dropped EXE
        Adds Run key to start application
        Drops file in System32 directory
        Drops file in Program Files directory
        Drops file in Windows directory
        Suspicious behavior: EnumeratesProcesses
        Suspicious use of AdjustPrivilegeToken
        Suspicious use of WriteProcessMemory
        
        PID:1080
      - C:\Windows\Professional\explorer.exe
        
        "C:\Windows\Professional\explorer.exe"
        6⤵
        Executes dropped EXE
        Suspicious behavior: EnumeratesProcesses
        Suspicious behavior: GetForegroundWindowSpam
        Suspicious use of AdjustPrivilegeToken
        
        PID:944

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "wininit" /sc ONLOGON /tr "'C:\Users\Default\wininit.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:616

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "explorer" /sc ONLOGON /tr "'C:\Program Files (x86)\Uninstall Information\explorer.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1700

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "Idle" /sc ONLOGON /tr "'C:\Program Files\VideoLAN\VLC\plugins\gui\Idle.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:788

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "cmd" /sc ONLOGON /tr "'C:\Windows\SysWOW64\Query\cmd.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1324

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "savesruntimeBrokerFontwin" /sc ONLOGON /tr "'C:\savesruntimeBroker\bB37mtqgliH1SYemgnxw\savesruntimeBrokerFontwin.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1756

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "explorer" /sc ONLOGON /tr "'C:\Windows\Professional\explorer.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1868

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhost" /sc ONLOGON /tr "'C:\Windows\System32\jscript9diag\dllhost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1148