dcrat | a2f2e7faee09ff22d394d74ca44ec2a153199d3af3936d1841f3d57c8eae721c

General

Target

MsSavesSessionDll/agentreviewPerf.exe
Size

2.3MB
MD5

4e69fcf73418a08fcb8b3e7e2ecb43c4
SHA1

a3ecd09f65ca4e7821a0b7f8596edcd679573f5b
SHA256

fa78ac8f4c94923c7e53a3bf6936b46aff02f7746ee9518460c2d529ea2982d4
SHA512

a6d1a2b6363ad8a560567e6c11a48f8d1bc4cdfc36474902edf39f676440be82619aae52279121a776486d0edfe7a448f0fe9707b27ae760c1d6dd0201f6adc3
SSDEEP

49152:BwpUwcTZ0rUinysyVZl5LCCcG3RTXM34FIIPWYJxuQfUgtFneJ8BG5U:Bw1ctUyjTLC8puaX/neJ8BgU

Score

10^/10

dcrat infostealer persistence rat

Malware Config

Signatures

DcRat 15 IoCs

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

rat infostealer dcrat

pid	Process
2884	schtasks.exe
2720	schtasks.exe
1032	schtasks.exe
2900	schtasks.exe
1488	schtasks.exe
2976	schtasks.exe
2544	schtasks.exe
2852	schtasks.exe
1916	schtasks.exe
2796	schtasks.exe
2744	schtasks.exe
2948	schtasks.exe
2848	schtasks.exe
2712	schtasks.exe
2764	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:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\", \"C:\\Program Files\\Uninstall Information\\System.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\", \"C:\\Program Files\\Uninstall Information\\System.exe\", \"C:\\MSOCache\\All Users\\spoolsv.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\", \"C:\\Program Files\\Uninstall Information\\System.exe\", \"C:\\MSOCache\\All Users\\spoolsv.exe\", \"C:\\Program Files (x86)\\Internet Explorer\\ja-JP\\WmiPrvSE.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\", \"C:\\Program Files\\Uninstall Information\\System.exe\", \"C:\\MSOCache\\All Users\\spoolsv.exe\", \"C:\\Program Files (x86)\\Internet Explorer\\ja-JP\\WmiPrvSE.exe\", \"C:\\Program Files\\Reference Assemblies\\audiodg.exe\""	agentreviewPerf.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	1488	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2884	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1032	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2900	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2948	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2796	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2976	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2544	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2848	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2712	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2852	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2744	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2720	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2764	2616	schtasks.exe	30
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1916	2616	schtasks.exe	30

DCRat payload 3 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral5/memory/2312-1-0x0000000000310000-0x0000000000562000-memory.dmp	dcrat
behavioral5/files/0x0005000000018744-18.dat	dcrat
behavioral5/memory/2136-27-0x0000000000C50000-0x0000000000EA2000-memory.dmp	dcrat

Executes dropped EXE 1 IoCs

pid	Process
2136	System.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\USER\S-1-5-21-1163522206-1469769407-485553996-1000\Software\Microsoft\Windows\CurrentVersion\Run\dwm = "\"C:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\dwm = "\"C:\\Recovery\\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\\dwm.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1163522206-1469769407-485553996-1000\Software\Microsoft\Windows\CurrentVersion\Run\System = "\"C:\\Program Files\\Uninstall Information\\System.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1163522206-1469769407-485553996-1000\Software\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\MSOCache\\All Users\\spoolsv.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\spoolsv = "\"C:\\MSOCache\\All Users\\spoolsv.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\System = "\"C:\\Program Files\\Uninstall Information\\System.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1163522206-1469769407-485553996-1000\Software\Microsoft\Windows\CurrentVersion\Run\WmiPrvSE = "\"C:\\Program Files (x86)\\Internet Explorer\\ja-JP\\WmiPrvSE.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\WmiPrvSE = "\"C:\\Program Files (x86)\\Internet Explorer\\ja-JP\\WmiPrvSE.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1163522206-1469769407-485553996-1000\Software\Microsoft\Windows\CurrentVersion\Run\audiodg = "\"C:\\Program Files\\Reference Assemblies\\audiodg.exe\""	agentreviewPerf.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\audiodg = "\"C:\\Program Files\\Reference Assemblies\\audiodg.exe\""	agentreviewPerf.exe

Drops file in Program Files directory 6 IoCs

description	ioc	Process
File created	C:\Program Files (x86)\Internet Explorer\ja-JP\24dbde2999530e	agentreviewPerf.exe
File created	C:\Program Files\Reference Assemblies\audiodg.exe	agentreviewPerf.exe
File created	C:\Program Files\Reference Assemblies\42af1c969fbb7b	agentreviewPerf.exe
File created	C:\Program Files\Uninstall Information\System.exe	agentreviewPerf.exe
File created	C:\Program Files\Uninstall Information\27d1bcfc3c54e0	agentreviewPerf.exe
File created	C:\Program Files (x86)\Internet Explorer\ja-JP\WmiPrvSE.exe	agentreviewPerf.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 15 IoCs

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

persistence execution

Scheduled Task

T1053.005

pid	Process
2796	schtasks.exe
2764	schtasks.exe
1488	schtasks.exe
2884	schtasks.exe
2948	schtasks.exe
2976	schtasks.exe
2848	schtasks.exe
1032	schtasks.exe
2900	schtasks.exe
2544	schtasks.exe
2712	schtasks.exe
2744	schtasks.exe
2720	schtasks.exe
2852	schtasks.exe
1916	schtasks.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
2312	agentreviewPerf.exe
2136	System.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2312	agentreviewPerf.exe
Token: SeDebugPrivilege	2136	System.exe

Suspicious use of WriteProcessMemory 3 IoCs

description	pid	Process	procid_target
PID 2312 wrote to memory of 2136	2312	agentreviewPerf.exe	46
PID 2312 wrote to memory of 2136	2312	agentreviewPerf.exe	46
PID 2312 wrote to memory of 2136	2312	agentreviewPerf.exe	46

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\MsSavesSessionDll\agentreviewPerf.exe
"C:\Users\Admin\AppData\Local\Temp\MsSavesSessionDll\agentreviewPerf.exe"
1⤵
- Modifies WinLogon for persistence
- Adds Run key to start application
- Drops file in Program Files directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2312
- C:\Program Files\Uninstall Information\System.exe
  "C:\Program Files\Uninstall Information\System.exe"
  2⤵
  - Executes dropped EXE
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  PID:2136

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dwmd" /sc MINUTE /mo 14 /tr "'C:\Recovery\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\dwm.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1488

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dwm" /sc ONLOGON /tr "'C:\Recovery\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\dwm.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2884

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dwmd" /sc MINUTE /mo 12 /tr "'C:\Recovery\480d7142-91a3-11ef-b9f6-6e5a89f5a3c7\dwm.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1032

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "SystemS" /sc MINUTE /mo 6 /tr "'C:\Program Files\Uninstall Information\System.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2900

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "System" /sc ONLOGON /tr "'C:\Program Files\Uninstall Information\System.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2948

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "SystemS" /sc MINUTE /mo 10 /tr "'C:\Program Files\Uninstall Information\System.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2796

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "spoolsvs" /sc MINUTE /mo 8 /tr "'C:\MSOCache\All Users\spoolsv.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2976

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:2544

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "spoolsvs" /sc MINUTE /mo 14 /tr "'C:\MSOCache\All Users\spoolsv.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2848

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "WmiPrvSEW" /sc MINUTE /mo 7 /tr "'C:\Program Files (x86)\Internet Explorer\ja-JP\WmiPrvSE.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2712

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "WmiPrvSE" /sc ONLOGON /tr "'C:\Program Files (x86)\Internet Explorer\ja-JP\WmiPrvSE.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2852

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "WmiPrvSEW" /sc MINUTE /mo 14 /tr "'C:\Program Files (x86)\Internet Explorer\ja-JP\WmiPrvSE.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2744

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "audiodga" /sc MINUTE /mo 11 /tr "'C:\Program Files\Reference Assemblies\audiodg.exe'" /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2720

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "audiodg" /sc ONLOGON /tr "'C:\Program Files\Reference Assemblies\audiodg.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2764

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "audiodga" /sc MINUTE /mo 13 /tr "'C:\Program Files\Reference Assemblies\audiodg.exe'" /rl HIGHEST /f
1⤵
- DcRat
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1916

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

Replay Monitor

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Downloads

C:\Program Files\Reference Assemblies\audiodg.exe

Filesize
2.3MB

MD5
4e69fcf73418a08fcb8b3e7e2ecb43c4

SHA1
a3ecd09f65ca4e7821a0b7f8596edcd679573f5b

SHA256
fa78ac8f4c94923c7e53a3bf6936b46aff02f7746ee9518460c2d529ea2982d4

SHA512
a6d1a2b6363ad8a560567e6c11a48f8d1bc4cdfc36474902edf39f676440be82619aae52279121a776486d0edfe7a448f0fe9707b27ae760c1d6dd0201f6adc3

Download Submit
memory/2136-30-0x0000000000300000-0x0000000000312000-memory.dmp

Filesize
72KB

Download
memory/2136-29-0x0000000000430000-0x0000000000486000-memory.dmp

Filesize
344KB

Download
memory/2136-27-0x0000000000C50000-0x0000000000EA2000-memory.dmp

Filesize
2.3MB

Download
memory/2312-6-0x00000000020E0000-0x00000000020F2000-memory.dmp

Filesize
72KB

Download
memory/2312-5-0x0000000000680000-0x00000000006D6000-memory.dmp

Filesize
344KB

Download
memory/2312-0-0x000007FEF5EC3000-0x000007FEF5EC4000-memory.dmp

Filesize
4KB

Download
memory/2312-7-0x0000000002110000-0x000000000211E000-memory.dmp

Filesize
56KB

Download
memory/2312-8-0x0000000002120000-0x0000000002128000-memory.dmp

Filesize
32KB

Download
memory/2312-9-0x0000000002130000-0x0000000002138000-memory.dmp

Filesize
32KB

Download
memory/2312-4-0x00000000005E0000-0x00000000005F6000-memory.dmp

Filesize
88KB

Download
memory/2312-3-0x00000000005C0000-0x00000000005DC000-memory.dmp

Filesize
112KB

Download
memory/2312-28-0x000007FEF5EC0000-0x000007FEF68AC000-memory.dmp

Filesize
9.9MB

Download
memory/2312-2-0x000007FEF5EC0000-0x000007FEF68AC000-memory.dmp

Filesize
9.9MB

Download
memory/2312-1-0x0000000000310000-0x0000000000562000-memory.dmp

Filesize
2.3MB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads