dcrat | 7fe5834f29daabc2f0034eff990a5dcadccdbbad7a6428eea416322020f2afef

General

Target

HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exe
Size

1.5MB
MD5

c532d809990659da1bc427ad039a7d5c
SHA1

6158717c914aea611074a14fd0527663e95ccb64
SHA256

7fe5834f29daabc2f0034eff990a5dcadccdbbad7a6428eea416322020f2afef
SHA512

b70d7d8f646d5bb1bb1a7bbd787c16647448d00291ed231b79e2193237d3ac1d00d584873cadccfea1a7494648a1c9050a056f42ce8d434a8b5318d4f2371d63
SSDEEP

12288:CC6105US81giZG7/N8vzvD//dH1P2TZeQmrD0:TUS813T

Score

10^/10

dcrat infostealer persistence rat

Malware Config

Signatures

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

Modifies WinLogon for persistence 2 TTPs 3 IoCs

persistence

Winlogon Helper DLL

T1004

Modify Registry

T1112

Processes:

WinNetCache.exe

description	ioc	process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\System32\\KBDDV\\csrss.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\System32\\KBDDV\\csrss.exe\", \"C:\\Windows\\System32\\C_10079\\spoolsv.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\System32\\KBDDV\\csrss.exe\", \"C:\\Windows\\System32\\C_10079\\spoolsv.exe\", \"C:\\Windows\\System32\\mciseq\\taskhost.exe\""	WinNetCache.exe

DCRat payload 6 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

Processes:

resource	yara_rule
C:\Users\Admin\AppData\Roaming\WinNetCache\WinNetCache.exe	dcrat
C:\Users\Admin\AppData\Roaming\WinNetCache\WinNetCache.exe	dcrat
behavioral1/memory/2040-58-0x0000000000D00000-0x0000000000D98000-memory.dmp	dcrat
C:\Windows\System32\C_10079\spoolsv.exe	dcrat
C:\Windows\System32\C_10079\spoolsv.exe	dcrat
behavioral1/memory/1020-66-0x0000000000A50000-0x0000000000AE8000-memory.dmp	dcrat

Executes dropped EXE 2 IoCs

Processes:

WinNetCache.exespoolsv.exe

pid process

2040 WinNetCache.exe
1020 spoolsv.exe

pid	process
2040	WinNetCache.exe
1020	spoolsv.exe

Adds Run key to start application 2 TTPs 6 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

Processes:

WinNetCache.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-3406023954-474543476-3319432036-1000\Software\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\Windows\\System32\\KBDDV\\csrss.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\Windows\\System32\\KBDDV\\csrss.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3406023954-474543476-3319432036-1000\Software\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\Windows\\System32\\C_10079\\spoolsv.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\Windows\\System32\\C_10079\\spoolsv.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3406023954-474543476-3319432036-1000\Software\Microsoft\Windows\CurrentVersion\Run\taskhost = "\"C:\\Windows\\System32\\mciseq\\taskhost.exe\""	WinNetCache.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\taskhost = "\"C:\\Windows\\System32\\mciseq\\taskhost.exe\""	WinNetCache.exe

Drops file in System32 directory 7 IoCs

Processes:

WinNetCache.exe

description	ioc	process
File created	C:\Windows\System32\mciseq\taskhost.exe	WinNetCache.exe
File created	C:\Windows\System32\mciseq\b75386f1303e64d8139363b71e44ac16341adf4e	WinNetCache.exe
File created	C:\Windows\System32\KBDDV\csrss.exe	WinNetCache.exe
File opened for modification	C:\Windows\System32\KBDDV\csrss.exe	WinNetCache.exe
File created	C:\Windows\System32\KBDDV\886983d96e3d3e31032c679b2d4ea91b6c05afef	WinNetCache.exe
File created	C:\Windows\System32\C_10079\spoolsv.exe	WinNetCache.exe
File created	C:\Windows\System32\C_10079\f3b6ecef712a24f33798f5d2fb3790c3d9b894c4	WinNetCache.exe

Drops file in Windows directory 1 IoCs

Processes:

WinNetCache.exe

description ioc process

File created C:\Windows\rescache\rc0002\services.exe WinNetCache.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

Processes:

schtasks.exeschtasks.exeschtasks.exe

pid process

1540 schtasks.exe
688 schtasks.exe
1552 schtasks.exe
Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

WinNetCache.exespoolsv.exe

pid process

2040 WinNetCache.exe
1020 spoolsv.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

WinNetCache.exespoolsv.exe

description pid process

Token: SeDebugPrivilege 2040 WinNetCache.exe
Token: SeDebugPrivilege 1020 spoolsv.exe

description	ioc	process
File created	C:\Windows\rescache\rc0002\services.exe	WinNetCache.exe

pid	process
1540	schtasks.exe
688	schtasks.exe
1552	schtasks.exe

pid	process
2040	WinNetCache.exe
1020	spoolsv.exe

description	pid	process
Token: SeDebugPrivilege	2040	WinNetCache.exe
Token: SeDebugPrivilege	1020	spoolsv.exe

Suspicious use of WriteProcessMemory 15 IoCs

Processes:

HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exeWinNetCache.exe

description	pid	process	target process
PID 1284 wrote to memory of 2040	1284	HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exe	WinNetCache.exe
PID 1284 wrote to memory of 2040	1284	HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exe	WinNetCache.exe
PID 1284 wrote to memory of 2040	1284	HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exe	WinNetCache.exe
PID 2040 wrote to memory of 1540	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 1540	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 1540	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 688	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 688	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 688	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 1552	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 1552	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 1552	2040	WinNetCache.exe	schtasks.exe
PID 2040 wrote to memory of 1020	2040	WinNetCache.exe	spoolsv.exe
PID 2040 wrote to memory of 1020	2040	WinNetCache.exe	spoolsv.exe
PID 2040 wrote to memory of 1020	2040	WinNetCache.exe	spoolsv.exe

C:\Users\Admin\AppData\Local\Temp\HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exe
"C:\Users\Admin\AppData\Local\Temp\HEUR-Trojan.Win32.Generic-7fe5834f29daabc2f00.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:1284

C:\Users\Admin\AppData\Roaming\WinNetCache\WinNetCache.exe
"C:\Users\Admin\AppData\Roaming\WinNetCache\WinNetCache.exe"
2⤵
- Modifies WinLogon for persistence
- Executes dropped EXE
- Adds Run key to start application
- Drops file in System32 directory
- Drops file in Windows directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2040

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "csrss" /sc ONLOGON /tr "'C:\Windows\System32\KBDDV\csrss.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1540

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "spoolsv" /sc ONLOGON /tr "'C:\Windows\System32\C_10079\spoolsv.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:688

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "taskhost" /sc ONLOGON /tr "'C:\Windows\System32\mciseq\taskhost.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1552

C:\Windows\System32\C_10079\spoolsv.exe
"C:\Windows\System32\C_10079\spoolsv.exe"
3⤵
- Executes dropped EXE
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:1020

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Scheduled Task

1

T1053

Persistence

Registry Run Keys / Startup Folder

Scheduled Task

Winlogon Helper DLL

Privilege Escalation

Scheduled Task

1

T1053

Defense Evasion

Modify Registry

2

T1112

Credential Access

Discovery

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Roaming\WinNetCache\WinNetCache.exe

Filesize
579KB

MD5
a5bb468e6bb248387e71ff2692106d47

SHA1
c673a5f6bee9ad99068a43455fac19cb4ffb948b

SHA256
5caa9414d268c408b9a82f4442a87efa2f7f4058d44de616a17da6c5ab113bc3

SHA512
fd8bdbb071ab7191ade1b19af740ceefd3743effa69c265a51bd98508aa62b73217e6fc99f19b09bd75d5403d71370a73575dd7fad3a9d1c679d0a1d7f3e743e

Download Submit
C:\Users\Admin\AppData\Roaming\WinNetCache\WinNetCache.exe

Filesize
579KB

MD5
a5bb468e6bb248387e71ff2692106d47

SHA1
c673a5f6bee9ad99068a43455fac19cb4ffb948b

SHA256
5caa9414d268c408b9a82f4442a87efa2f7f4058d44de616a17da6c5ab113bc3

SHA512
fd8bdbb071ab7191ade1b19af740ceefd3743effa69c265a51bd98508aa62b73217e6fc99f19b09bd75d5403d71370a73575dd7fad3a9d1c679d0a1d7f3e743e

Download Submit
C:\Windows\System32\C_10079\spoolsv.exe

Filesize
579KB

MD5
a5bb468e6bb248387e71ff2692106d47

SHA1
c673a5f6bee9ad99068a43455fac19cb4ffb948b

SHA256
5caa9414d268c408b9a82f4442a87efa2f7f4058d44de616a17da6c5ab113bc3

SHA512
fd8bdbb071ab7191ade1b19af740ceefd3743effa69c265a51bd98508aa62b73217e6fc99f19b09bd75d5403d71370a73575dd7fad3a9d1c679d0a1d7f3e743e

Download Submit
C:\Windows\System32\C_10079\spoolsv.exe

Filesize
579KB

MD5
a5bb468e6bb248387e71ff2692106d47

SHA1
c673a5f6bee9ad99068a43455fac19cb4ffb948b

SHA256
5caa9414d268c408b9a82f4442a87efa2f7f4058d44de616a17da6c5ab113bc3

SHA512
fd8bdbb071ab7191ade1b19af740ceefd3743effa69c265a51bd98508aa62b73217e6fc99f19b09bd75d5403d71370a73575dd7fad3a9d1c679d0a1d7f3e743e

Download Submit
memory/688-60-0x0000000000000000-mapping.dmp

Download
memory/1020-63-0x0000000000000000-mapping.dmp

Download
memory/1020-66-0x0000000000A50000-0x0000000000AE8000-memory.dmp

Filesize
608KB

Download
memory/1284-54-0x0000000000C60000-0x0000000000DEA000-memory.dmp

Filesize
1.5MB

Download
memory/1540-59-0x0000000000000000-mapping.dmp

Download
memory/1552-61-0x0000000000000000-mapping.dmp

Download
memory/2040-62-0x000007FEFBF31000-0x000007FEFBF33000-memory.dmp

Filesize
8KB

Download
memory/2040-58-0x0000000000D00000-0x0000000000D98000-memory.dmp

Filesize
608KB

Download
memory/2040-55-0x0000000000000000-mapping.dmp

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads