dcrat | 21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e

General

Target

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe
Size

4.6MB
MD5

43334042325d6a1a3ae84729cb8b5cb0
SHA1

a1552e1c54b9024db5b75df401f76e510086c80e
SHA256

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e
SHA512

c08e24a7197af85f0446404ba0531cd81d313712b2f83e394b498bc842604f15b181bc93d8220959df315c5e2e7da71b2b25a1ce770e18590f9f2095bef74c61
SSDEEP

98304:IFV3lDzCOXPy7Qf5Iyc4i4iKK8hdC3FuxefuAU8sKzdCu:IdCOVcjmdSF2shzd7

Score

10^/10

dcrat evasion infostealer persistence rat themida trojan

Malware Config

Signatures

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

DCRat payload 8 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

Processes:

resource	yara_rule
behavioral2/memory/4112-138-0x0000000000CB0000-0x000000000179C000-memory.dmp	dcrat
behavioral2/memory/4112-139-0x0000000000CB0000-0x000000000179C000-memory.dmp	dcrat
C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe	dcrat
C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe	dcrat
behavioral2/memory/4716-149-0x00000297ADF00000-0x00000297AE044000-memory.dmp	dcrat
behavioral2/memory/4112-150-0x0000000000CB0000-0x000000000179C000-memory.dmp	dcrat
C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe	dcrat
C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe	dcrat

Identifies VirtualBox via ACPI registry values (likely anti-VM) 2 TTPs 1 IoCs
evasion

Query Registry
T1012

Virtualization/Sandbox Evasion
T1497

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

description ioc process

Key opened \REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__ 21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe
Executes dropped EXE 3 IoCs

Processes:

RustOptimizationTool.exeRustOptimizationSettings.exeSystem.exe

pid process

4732 RustOptimizationTool.exe
4716 RustOptimizationSettings.exe
4612 System.exe

description	ioc	process
Key opened	\REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

pid	process
4732	RustOptimizationTool.exe
4716	RustOptimizationSettings.exe
4612	System.exe

Checks BIOS information in registry 2 TTPs 2 IoCs

BIOS information is often read in order to detect sandboxing environments.

Query Registry

T1012

System Information Discovery

T1082

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

description	ioc	process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

Checks computer location settings 2 TTPs 1 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

T1012

System Information Discovery

T1082

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

description	ioc	process
Key value queried	\REGISTRY\USER\S-1-5-21-2295526160-1155304984-640977766-1000\Control Panel\International\Geo\Nation	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

Themida packer 3 IoCs

Detects Themida, an advanced Windows software protection system.

themida

Processes:

resource	yara_rule
behavioral2/memory/4112-138-0x0000000000CB0000-0x000000000179C000-memory.dmp	themida
behavioral2/memory/4112-139-0x0000000000CB0000-0x000000000179C000-memory.dmp	themida
behavioral2/memory/4112-150-0x0000000000CB0000-0x000000000179C000-memory.dmp	themida

Adds Run key to start application 2 TTPs 5 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

Processes:

RustOptimizationSettings.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-2295526160-1155304984-640977766-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\conhost = "\"C:\\Windows\\PLA\\Templates\\conhost.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-2295526160-1155304984-640977766-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\csrss = "\"C:\\Program Files (x86)\\Google\\CrashReports\\csrss.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-2295526160-1155304984-640977766-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\conhost = "\"C:\\Users\\Admin\\Saved Games\\conhost.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-2295526160-1155304984-640977766-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\conhost = "\"C:\\odt\\conhost.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-2295526160-1155304984-640977766-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\StartMenuExperienceHost = "\"C:\\Program Files (x86)\\WindowsPowerShell\\Modules\\PowerShellGet\\1.0.0.1\\es-ES\\StartMenuExperienceHost.exe\""	RustOptimizationSettings.exe

Checks whether UAC is enabled 1 TTPs 1 IoCs

evasion trojan

System Information Discovery

T1082

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

description	ioc	process
Key value queried	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

Suspicious use of NtSetInformationThreadHideFromDebugger 1 IoCs

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

pid process

4112 21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

pid	process
4112	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

Drops file in Program Files directory 4 IoCs

Processes:

RustOptimizationSettings.exe

description	ioc	process
File created	C:\Program Files (x86)\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\es-ES\55b276f4edf653fe07efe8f1ecc32d3d195abd16	RustOptimizationSettings.exe
File created	C:\Program Files (x86)\Google\CrashReports\csrss.exe	RustOptimizationSettings.exe
File created	C:\Program Files (x86)\Google\CrashReports\886983d96e3d3e31032c679b2d4ea91b6c05afef	RustOptimizationSettings.exe
File created	C:\Program Files (x86)\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\es-ES\StartMenuExperienceHost.exe	RustOptimizationSettings.exe

Drops file in Windows directory 5 IoCs

Processes:

RustOptimizationSettings.exe

description	ioc	process
File created	C:\Windows\PLA\Templates\conhost.exe	RustOptimizationSettings.exe
File opened for modification	C:\Windows\PLA\Templates\conhost.exe	RustOptimizationSettings.exe
File created	C:\Windows\PLA\Templates\088424020bedd6b28ac7fd22ee35dcd7322895ce	RustOptimizationSettings.exe
File created	C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe	RustOptimizationSettings.exe
File created	C:\Windows\SystemResources\Windows.UI.Shell\pris\27d1bcfc3c54e0e44ea423ffd4ee81fe73670a2a	RustOptimizationSettings.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 6 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
persistence

Scheduled Task
T1053

Processes:

schtasks.exeschtasks.exeschtasks.exeschtasks.exeschtasks.exeschtasks.exe

pid process

3764 schtasks.exe
3692 schtasks.exe
1656 schtasks.exe
3732 schtasks.exe
3388 schtasks.exe
3416 schtasks.exe
Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

RustOptimizationSettings.exeSystem.exe

pid process

4716 RustOptimizationSettings.exe
4612 System.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

RustOptimizationSettings.exeSystem.exe

description pid process

Token: SeDebugPrivilege 4716 RustOptimizationSettings.exe
Token: SeDebugPrivilege 4612 System.exe

pid	process
3764	schtasks.exe
3692	schtasks.exe
1656	schtasks.exe
3732	schtasks.exe
3388	schtasks.exe
3416	schtasks.exe

pid	process
4716	RustOptimizationSettings.exe
4612	System.exe

description	pid	process
Token: SeDebugPrivilege	4716	RustOptimizationSettings.exe
Token: SeDebugPrivilege	4612	System.exe

Suspicious use of WriteProcessMemory 19 IoCs

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exeRustOptimizationSettings.exe

description	pid	process	target process
PID 4112 wrote to memory of 4732	4112	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 4112 wrote to memory of 4732	4112	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 4112 wrote to memory of 4732	4112	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 4112 wrote to memory of 4716	4112	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationSettings.exe
PID 4112 wrote to memory of 4716	4112	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationSettings.exe
PID 4716 wrote to memory of 3764	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3764	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3692	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3692	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 1656	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 1656	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3732	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3732	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3388	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3388	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3416	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 3416	4716	RustOptimizationSettings.exe	schtasks.exe
PID 4716 wrote to memory of 4612	4716	RustOptimizationSettings.exe	System.exe
PID 4716 wrote to memory of 4612	4716	RustOptimizationSettings.exe	System.exe

C:\Users\Admin\AppData\Local\Temp\21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe
"C:\Users\Admin\AppData\Local\Temp\21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe"
1⤵
- Identifies VirtualBox via ACPI registry values (likely anti-VM)
- Checks BIOS information in registry
- Checks computer location settings
- Checks whether UAC is enabled
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Suspicious use of WriteProcessMemory
PID:4112

C:\Users\Admin\AppData\Local\Temp\RustOptimizationTool.exe
"C:\Users\Admin\AppData\Local\Temp\RustOptimizationTool.exe"
2⤵
- Executes dropped EXE
PID:4732

C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe
"C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe"
2⤵
- Executes dropped EXE
- Adds Run key to start application
- Drops file in Program Files directory
- Drops file in Windows directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:4716

C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "conhost" /sc ONLOGON /tr "'C:\Windows\PLA\Templates\conhost.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:3764

C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "csrss" /sc ONLOGON /tr "'C:\Program Files (x86)\Google\CrashReports\csrss.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:3692

C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "conhost" /sc ONLOGON /tr "'C:\Users\Admin\Saved Games\conhost.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1656

C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "conhost" /sc ONLOGON /tr "'C:\odt\conhost.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:3732

C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "StartMenuExperienceHost" /sc ONLOGON /tr "'C:\Program Files (x86)\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\es-ES\StartMenuExperienceHost.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:3388

C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "System" /sc ONLOGON /tr "'C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:3416

C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe
"C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe"
3⤵
- Executes dropped EXE
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:4612

Network

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Scheduled Task

1

T1053

Persistence

Registry Run Keys / Startup Folder

1

T1060

Scheduled Task

1

T1053

Privilege Escalation

Scheduled Task

1

T1053

Defense Evasion

Virtualization/Sandbox Evasion

1

T1497

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

3

T1012

Virtualization/Sandbox Evasion

1

T1497

System Information Discovery

4

T1082

Lateral Movement

Collection

Exfiltration

Command and Control

Impact

Replay Monitor

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Downloads

C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe
Filesize
1.2MB

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

Download Submit
C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe
Filesize
1.2MB

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

Download Submit
C:\Users\Admin\AppData\Local\Temp\RustOptimizationTool.exe
Filesize
5KB

MD5
f177a8a583b8410d7b2a715de831f1d6

SHA1
9329c2aafa6d53625383d2cf1a5cc198b44e1c78

SHA256
d4308a409a20c1d60a85dfb314c450d4f2db00f671a77f8ddf5d8c629a81d619

SHA512
78b610539378581288e721e166ce33d9b9a77841a49381fd6fa88eb7fe299aa857efcec34f8c2987ce56c45215e8be421776956b5c7c57f6f082f35c75d89735

Download Submit
C:\Users\Admin\AppData\Local\Temp\RustOptimizationTool.exe
Filesize
5KB

MD5
f177a8a583b8410d7b2a715de831f1d6

SHA1
9329c2aafa6d53625383d2cf1a5cc198b44e1c78

SHA256
d4308a409a20c1d60a85dfb314c450d4f2db00f671a77f8ddf5d8c629a81d619

SHA512
78b610539378581288e721e166ce33d9b9a77841a49381fd6fa88eb7fe299aa857efcec34f8c2987ce56c45215e8be421776956b5c7c57f6f082f35c75d89735

Download Submit
C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe
Filesize
1.2MB

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

Download Submit
C:\Windows\SystemResources\Windows.UI.Shell\pris\System.exe
Filesize
1.2MB

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

Download Submit
memory/1656-156-0x0000000000000000-mapping.dmp

Download
memory/3388-158-0x0000000000000000-mapping.dmp

Download
memory/3416-159-0x0000000000000000-mapping.dmp

Download
memory/3692-155-0x0000000000000000-mapping.dmp

Download
memory/3732-157-0x0000000000000000-mapping.dmp

Download
memory/3764-154-0x0000000000000000-mapping.dmp

Download
memory/4112-141-0x0000000077520000-0x00000000776C3000-memory.dmp

Filesize
1.6MB

Download
memory/4112-132-0x0000000000CB0000-0x000000000179C000-memory.dmp

Filesize
10.9MB

Download
memory/4112-150-0x0000000000CB0000-0x000000000179C000-memory.dmp

Filesize
10.9MB

Download
memory/4112-151-0x0000000077520000-0x00000000776C3000-memory.dmp

Filesize
1.6MB

Download
memory/4112-140-0x00000000064E0000-0x0000000006A84000-memory.dmp

Filesize
5.6MB

Download
memory/4112-139-0x0000000000CB0000-0x000000000179C000-memory.dmp

Filesize
10.9MB

Download
memory/4112-138-0x0000000000CB0000-0x000000000179C000-memory.dmp

Filesize
10.9MB

Download
memory/4112-134-0x0000000077520000-0x00000000776C3000-memory.dmp

Filesize
1.6MB

Download
memory/4112-133-0x0000000000CB0000-0x000000000179C000-memory.dmp

Filesize
10.9MB

Download
memory/4612-164-0x00007FFFDEF20000-0x00007FFFDF9E1000-memory.dmp

Filesize
10.8MB

Download
memory/4612-165-0x00007FFFDEF20000-0x00007FFFDF9E1000-memory.dmp

Filesize
10.8MB

Download
memory/4612-160-0x0000000000000000-mapping.dmp

Download
memory/4716-149-0x00000297ADF00000-0x00000297AE044000-memory.dmp

Filesize
1.3MB

Download
memory/4716-153-0x00007FFFDEF20000-0x00007FFFDF9E1000-memory.dmp

Filesize
10.8MB

Download
memory/4716-152-0x00007FFFDEF20000-0x00007FFFDF9E1000-memory.dmp

Filesize
10.8MB

Download
memory/4716-163-0x00007FFFDEF20000-0x00007FFFDF9E1000-memory.dmp

Filesize
10.8MB

Download
memory/4716-145-0x0000000000000000-mapping.dmp

Download
memory/4732-148-0x0000000000530000-0x0000000000538000-memory.dmp

Filesize
32KB

Download
memory/4732-142-0x0000000000000000-mapping.dmp

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Matrix ATT&CK v6

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Downloads