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 10 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

Processes:

resource	yara_rule
behavioral1/memory/896-60-0x0000000000060000-0x0000000000B4C000-memory.dmp	dcrat
behavioral1/memory/896-61-0x0000000000060000-0x0000000000B4C000-memory.dmp	dcrat
\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe	dcrat
C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe	dcrat
behavioral1/memory/896-71-0x0000000000060000-0x0000000000B4C000-memory.dmp	dcrat
C:\Users\Admin\AppData\Local\Temp\RustOptimizationSettings.exe	dcrat
behavioral1/memory/1996-73-0x0000000000180000-0x00000000002C4000-memory.dmp	dcrat
C:\Users\Default\Music\RustOptimizationSettings.exe	dcrat
C:\Users\Default\Music\RustOptimizationSettings.exe	dcrat
behavioral1/memory/672-83-0x0000000000CD0000-0x0000000000E14000-memory.dmp	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.exeRustOptimizationSettings.exe

pid process

2040 RustOptimizationTool.exe
1996 RustOptimizationSettings.exe
672 RustOptimizationSettings.exe

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

pid	process
2040	RustOptimizationTool.exe
1996	RustOptimizationSettings.exe
672	RustOptimizationSettings.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

Loads dropped DLL 2 IoCs

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

pid	process
896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe
896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

Themida packer 3 IoCs

Detects Themida, an advanced Windows software protection system.

themida

Processes:

resource	yara_rule
behavioral1/memory/896-60-0x0000000000060000-0x0000000000B4C000-memory.dmp	themida
behavioral1/memory/896-61-0x0000000000060000-0x0000000000B4C000-memory.dmp	themida
behavioral1/memory/896-71-0x0000000000060000-0x0000000000B4C000-memory.dmp	themida

Adds Run key to start application 2 TTPs 6 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

Processes:

RustOptimizationSettings.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-3845472200-3839195424-595303356-1000\Software\Microsoft\Windows\CurrentVersion\Run\wininit = "\"C:\\Users\\Public\\Pictures\\Sample Pictures\\wininit.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3845472200-3839195424-595303356-1000\Software\Microsoft\Windows\CurrentVersion\Run\RustOptimizationTool = "\"C:\\ProgramData\\Package Cache\\RustOptimizationTool.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3845472200-3839195424-595303356-1000\Software\Microsoft\Windows\CurrentVersion\Run\services = "\"C:\\ProgramData\\Adobe\\Updater6\\services.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3845472200-3839195424-595303356-1000\Software\Microsoft\Windows\CurrentVersion\Run\System = "\"C:\\Windows\\SoftwareDistribution\\Download\\System.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3845472200-3839195424-595303356-1000\Software\Microsoft\Windows\CurrentVersion\Run\taskhost = "\"C:\\MSOCache\\All Users\\{90140000-0011-0000-0000-0000000FF1CE}-C\\taskhost.exe\""	RustOptimizationSettings.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3845472200-3839195424-595303356-1000\Software\Microsoft\Windows\CurrentVersion\Run\RustOptimizationSettings = "\"C:\\Users\\Default\\Music\\RustOptimizationSettings.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

896 21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe

Drops file in Windows directory 2 IoCs

Processes:

RustOptimizationSettings.exe

description	ioc	process
File created	C:\Windows\SoftwareDistribution\Download\System.exe	RustOptimizationSettings.exe
File created	C:\Windows\SoftwareDistribution\Download\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

284 schtasks.exe
524 schtasks.exe
1484 schtasks.exe
1532 schtasks.exe
1564 schtasks.exe
1152 schtasks.exe
Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

RustOptimizationSettings.exeRustOptimizationSettings.exe

pid process

1996 RustOptimizationSettings.exe
672 RustOptimizationSettings.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

RustOptimizationSettings.exeRustOptimizationSettings.exe

description pid process

Token: SeDebugPrivilege 1996 RustOptimizationSettings.exe
Token: SeDebugPrivilege 672 RustOptimizationSettings.exe

pid	process
284	schtasks.exe
524	schtasks.exe
1484	schtasks.exe
1532	schtasks.exe
1564	schtasks.exe
1152	schtasks.exe

pid	process
1996	RustOptimizationSettings.exe
672	RustOptimizationSettings.exe

description	pid	process
Token: SeDebugPrivilege	1996	RustOptimizationSettings.exe
Token: SeDebugPrivilege	672	RustOptimizationSettings.exe

Suspicious use of WriteProcessMemory 29 IoCs

Processes:

21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exeRustOptimizationSettings.exe

description	pid	process	target process
PID 896 wrote to memory of 2040	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 896 wrote to memory of 2040	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 896 wrote to memory of 2040	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 896 wrote to memory of 2040	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationTool.exe
PID 896 wrote to memory of 1996	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationSettings.exe
PID 896 wrote to memory of 1996	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationSettings.exe
PID 896 wrote to memory of 1996	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationSettings.exe
PID 896 wrote to memory of 1996	896	21a9f82942e3d5b88a1180b1d6bc2082648db67d2d0257b67d07fe531ecfef0e.exe	RustOptimizationSettings.exe
PID 1996 wrote to memory of 1152	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1152	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1152	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 284	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 284	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 284	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 524	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 524	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 524	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1484	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1484	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1484	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1532	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1532	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1532	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1564	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1564	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 1564	1996	RustOptimizationSettings.exe	schtasks.exe
PID 1996 wrote to memory of 672	1996	RustOptimizationSettings.exe	RustOptimizationSettings.exe
PID 1996 wrote to memory of 672	1996	RustOptimizationSettings.exe	RustOptimizationSettings.exe
PID 1996 wrote to memory of 672	1996	RustOptimizationSettings.exe	RustOptimizationSettings.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
- Loads dropped DLL
- Checks whether UAC is enabled
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Suspicious use of WriteProcessMemory
PID:896

C:\Users\Admin\AppData\Local\Temp\RustOptimizationTool.exe
"C:\Users\Admin\AppData\Local\Temp\RustOptimizationTool.exe"
2⤵
- Executes dropped EXE
PID:2040

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 Windows directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1996

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "wininit" /sc ONLOGON /tr "'C:\Users\Public\Pictures\Sample Pictures\wininit.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1152

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "RustOptimizationTool" /sc ONLOGON /tr "'C:\ProgramData\Package Cache\RustOptimizationTool.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:284

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "services" /sc ONLOGON /tr "'C:\ProgramData\Adobe\Updater6\services.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:524

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "System" /sc ONLOGON /tr "'C:\Windows\SoftwareDistribution\Download\System.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1484

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "taskhost" /sc ONLOGON /tr "'C:\MSOCache\All Users\{90140000-0011-0000-0000-0000000FF1CE}-C\taskhost.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1532

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "RustOptimizationSettings" /sc ONLOGON /tr "'C:\Users\Default\Music\RustOptimizationSettings.exe'" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:1564

C:\Users\Default\Music\RustOptimizationSettings.exe
"C:\Users\Default\Music\RustOptimizationSettings.exe"
3⤵
- Executes dropped EXE
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:672

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

2

T1012

Virtualization/Sandbox Evasion

1

T1497

System Information Discovery

3

T1082

Lateral Movement

Collection

Exfiltration

Command and Control

Impact

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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:\Users\Default\Music\RustOptimizationSettings.exe
Filesize
1.2MB

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

Download Submit
C:\Users\Default\Music\RustOptimizationSettings.exe
Filesize
1.2MB

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

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

MD5
fd1604c0a2a2dd9369703c37628fbbb8

SHA1
2eef0012fe1f46cef5f3004b71e50c1a9f404375

SHA256
db9b04fd7fcd43c44dc0619d329f5d2ed11b17a9b6e7ca98b46bf6955eb978b9

SHA512
134d987a23796209d7c51782c6f5bc84fe9b78c8b4555d32ef27e75ddcb1c96bae68260cf5cf96d03248ea2bb1f90bf7e55e9307ecbb58290dc06fad76c7965a

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

MD5
f177a8a583b8410d7b2a715de831f1d6

SHA1
9329c2aafa6d53625383d2cf1a5cc198b44e1c78

SHA256
d4308a409a20c1d60a85dfb314c450d4f2db00f671a77f8ddf5d8c629a81d619

SHA512
78b610539378581288e721e166ce33d9b9a77841a49381fd6fa88eb7fe299aa857efcec34f8c2987ce56c45215e8be421776956b5c7c57f6f082f35c75d89735

Download Submit
memory/284-75-0x0000000000000000-mapping.dmp

Download
memory/524-76-0x0000000000000000-mapping.dmp

Download
memory/672-83-0x0000000000CD0000-0x0000000000E14000-memory.dmp

Filesize
1.3MB

Download
memory/672-80-0x0000000000000000-mapping.dmp

Download
memory/896-54-0x0000000000060000-0x0000000000B4C000-memory.dmp

Filesize
10.9MB

Download
memory/896-56-0x0000000077AC0000-0x0000000077C40000-memory.dmp

Filesize
1.5MB

Download
memory/896-55-0x0000000075D01000-0x0000000075D03000-memory.dmp

Filesize
8KB

Download
memory/896-72-0x0000000077AC0000-0x0000000077C40000-memory.dmp

Filesize
1.5MB

Download
memory/896-61-0x0000000000060000-0x0000000000B4C000-memory.dmp

Filesize
10.9MB

Download
memory/896-60-0x0000000000060000-0x0000000000B4C000-memory.dmp

Filesize
10.9MB

Download
memory/896-71-0x0000000000060000-0x0000000000B4C000-memory.dmp

Filesize
10.9MB

Download
memory/1152-74-0x0000000000000000-mapping.dmp

Download
memory/1484-77-0x0000000000000000-mapping.dmp

Download
memory/1532-78-0x0000000000000000-mapping.dmp

Download
memory/1564-79-0x0000000000000000-mapping.dmp

Download
memory/1996-73-0x0000000000180000-0x00000000002C4000-memory.dmp

Filesize
1.3MB

Download
memory/1996-66-0x0000000000000000-mapping.dmp

Download
memory/2040-63-0x0000000000000000-mapping.dmp

Download
memory/2040-70-0x0000000000920000-0x0000000000928000-memory.dmp

Filesize
32KB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Matrix ATT&CK v6

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Downloads