dcrat | 7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930

General

Target

7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Size

4.1MB
MD5

fc12e64914d68aa8fcacfe14eac14973
SHA1

ffb90d0353325044a8e77a1b3d32c157e522ec6e
SHA256

7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930
SHA512

6d2ff1530504b6a3fccb9bc2fce1e0844b5d901407af185b7b9b827896cfce26ea97f230d1f68ee577cf1665a4d0d2fe5b34532634dcc2bd05d5ff2ce77fbae0
SSDEEP

98304:cBLZABTF8Ic94u3YveXYBLZABTF8Ic94u3YveXB:cBZAB+33Y2oBZAB+33Y2x

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
Dcrat family
dcrat

Modifies WinLogon for persistence 2 TTPs 4 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:\\Windows\\System32\\usk\\wininit.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\System32\\usk\\wininit.exe\", \"C:\\Windows\\System32\\dmocx\\wininit.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\System32\\usk\\wininit.exe\", \"C:\\Windows\\System32\\dmocx\\wininit.exe\", \"C:\\ProgramData\\Microsoft Help\\csrss.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\System32\\usk\\wininit.exe\", \"C:\\Windows\\System32\\dmocx\\wininit.exe\", \"C:\\ProgramData\\Microsoft Help\\csrss.exe\", \"C:\\Windows\\System32\\wpcsvc\\dllhost.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe

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	2772	588	schtasks.exe	31
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2788	588	schtasks.exe	31
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	3052	588	schtasks.exe	31
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2764	588	schtasks.exe	31

DCRat payload 3 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral1/memory/2352-1-0x0000000000060000-0x000000000026E000-memory.dmp	dcrat
behavioral1/files/0x000900000001756b-11.dat	dcrat
behavioral1/memory/2792-18-0x00000000003A0000-0x00000000005AE000-memory.dmp	dcrat

Executes dropped EXE 1 IoCs

pid	Process
2792	csrss.exe

Adds Run key to start application 2 TTPs 8 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\wininit = "\"C:\\Windows\\System32\\dmocx\\wininit.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\wininit = "\"C:\\Windows\\System32\\dmocx\\wininit.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\ProgramData\\Microsoft Help\\csrss.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\ProgramData\\Microsoft Help\\csrss.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Windows\\System32\\wpcsvc\\dllhost.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Windows\\System32\\wpcsvc\\dllhost.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\wininit = "\"C:\\Windows\\System32\\usk\\wininit.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\wininit = "\"C:\\Windows\\System32\\usk\\wininit.exe\""	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe

Drops file in System32 directory 7 IoCs

description	ioc	Process
File created	C:\Windows\System32\usk\560854153607923c4c5f107085a7db67be01f252	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
File created	C:\Windows\System32\dmocx\wininit.exe	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
File created	C:\Windows\System32\dmocx\560854153607923c4c5f107085a7db67be01f252	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
File created	C:\Windows\System32\wpcsvc\dllhost.exe	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
File created	C:\Windows\System32\wpcsvc\5940a34987c99120d96dace90a3f93f329dcad63	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
File created	C:\Windows\System32\usk\wininit.exe	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
File opened for modification	C:\Windows\System32\usk\wininit.exe	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe

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

System Information Discovery
T1082

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
2772	schtasks.exe
2788	schtasks.exe
3052	schtasks.exe
2764	schtasks.exe

Suspicious behavior: EnumeratesProcesses 5 IoCs

pid	Process
2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
2792	csrss.exe
2792	csrss.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
Token: SeDebugPrivilege	2792	csrss.exe

Suspicious use of WriteProcessMemory 3 IoCs

description	pid	Process	procid_target
PID 2352 wrote to memory of 2792	2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe	36
PID 2352 wrote to memory of 2792	2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe	36
PID 2352 wrote to memory of 2792	2352	7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe	36

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\7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe
"C:\Users\Admin\AppData\Local\Temp\7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930.exe"
1⤵
- Modifies WinLogon for persistence
- Adds Run key to start application
- Drops file in System32 directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2352
- C:\ProgramData\Microsoft Help\csrss.exe
  "C:\ProgramData\Microsoft Help\csrss.exe"
  2⤵
  - Executes dropped EXE
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  PID:2792

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "wininit" /sc ONLOGON /tr "'C:\Windows\System32\usk\wininit.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2772

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "wininit" /sc ONLOGON /tr "'C:\Windows\System32\dmocx\wininit.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2788

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\ProgramData\Microsoft Help\csrss.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:3052

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhost" /sc ONLOGON /tr "'C:\Windows\System32\wpcsvc\dllhost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2764

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

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\ProgramData\Microsoft Help\csrss.exe

Filesize
4.1MB

MD5
fc12e64914d68aa8fcacfe14eac14973

SHA1
ffb90d0353325044a8e77a1b3d32c157e522ec6e

SHA256
7a51c74f9e3082a8fdc5b2aa00d105ac565ed3a696b7b59ec562f0a15cf77930

SHA512
6d2ff1530504b6a3fccb9bc2fce1e0844b5d901407af185b7b9b827896cfce26ea97f230d1f68ee577cf1665a4d0d2fe5b34532634dcc2bd05d5ff2ce77fbae0

Download Submit
memory/2352-0-0x000007FEF60D3000-0x000007FEF60D4000-memory.dmp

Filesize
4KB

Download
memory/2352-1-0x0000000000060000-0x000000000026E000-memory.dmp

Filesize
2.1MB

Download
memory/2352-2-0x000007FEF60D0000-0x000007FEF6ABC000-memory.dmp

Filesize
9.9MB

Download
memory/2352-17-0x000007FEF60D0000-0x000007FEF6ABC000-memory.dmp

Filesize
9.9MB

Download
memory/2792-21-0x0000000000350000-0x0000000000358000-memory.dmp

Filesize
32KB

Download
memory/2792-19-0x0000000000340000-0x000000000034C000-memory.dmp

Filesize
48KB

Download
memory/2792-22-0x00000000006B0000-0x0000000000706000-memory.dmp

Filesize
344KB

Download
memory/2792-18-0x00000000003A0000-0x00000000005AE000-memory.dmp

Filesize
2.1MB

Download
memory/2792-20-0x0000000000360000-0x0000000000368000-memory.dmp

Filesize
32KB

Download
memory/2792-24-0x0000000000390000-0x000000000039C000-memory.dmp

Filesize
48KB

Download
memory/2792-23-0x0000000000380000-0x0000000000388000-memory.dmp

Filesize
32KB

Download
memory/2792-28-0x0000000000930000-0x0000000000938000-memory.dmp

Filesize
32KB

Download
memory/2792-27-0x0000000000710000-0x0000000000718000-memory.dmp

Filesize
32KB

Download
memory/2792-26-0x0000000000700000-0x0000000000708000-memory.dmp

Filesize
32KB

Download
memory/2792-25-0x0000000000370000-0x0000000000378000-memory.dmp

Filesize
32KB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads