dcrat | 1e9b61bacadec88ed81039e5551de06d39f558694e5756bbe7aa92d46ba488a5

General

Target

90125421267c6f2a55fb1566eac89528.exe
Size

1.1MB
MD5

90125421267c6f2a55fb1566eac89528
SHA1

eb56f971b495461dce763a4680b96c4e07d5a1b5
SHA256

1e9b61bacadec88ed81039e5551de06d39f558694e5756bbe7aa92d46ba488a5
SHA512

e36d7cccf5c4e7aa134a922e7d5b735cc4ab5094dd4cdb2a4407c33934459871b412c7f8d4c527d75f04535ca592fd1a354a718925ef7a21a6a28e2b02d58d6f
SSDEEP

24576:KCEPLqs02vS7YlgdGNrY6JtfcDc8a24C2xSeq9Ra+4:KCCx0XIUUmRN

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

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	1872	5016	schtasks.exe	84
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1216	5016	schtasks.exe	84
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1844	5016	schtasks.exe	84
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2648	5016	schtasks.exe	84

DCRat payload 2 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral2/memory/1568-0-0x0000000000A00000-0x0000000000B22000-memory.dmp	dcrat
behavioral2/files/0x000600000002321d-19.dat	dcrat

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

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-996941297-2279405024-2328152752-1000\Control Panel\International\Geo\Nation	90125421267c6f2a55fb1566eac89528.exe

Executes dropped EXE 1 IoCs

pid	Process
2396	winlogon.exe

Adds Run key to start application 2 TTPs 4 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\SppExtComObj = "\"C:\\Documents and Settings\\SppExtComObj.exe\""	90125421267c6f2a55fb1566eac89528.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\WmiPrvSE = "\"C:\\Windows\\System32\\wbem\\Win32_DeviceGuard\\WmiPrvSE.exe\""	90125421267c6f2a55fb1566eac89528.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\RuntimeBroker = "\"C:\\Windows\\System32\\mfc110u\\RuntimeBroker.exe\""	90125421267c6f2a55fb1566eac89528.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\winlogon = "\"C:\\Documents and Settings\\winlogon.exe\""	90125421267c6f2a55fb1566eac89528.exe

Drops file in System32 directory 5 IoCs

description	ioc	Process
File opened for modification	C:\Windows\System32\mfc110u\RuntimeBroker.exe	90125421267c6f2a55fb1566eac89528.exe
File created	C:\Windows\System32\mfc110u\9e8d7a4ca61bd92aff00cc37a7a4d62a2cac998d	90125421267c6f2a55fb1566eac89528.exe
File created	C:\Windows\System32\wbem\Win32_DeviceGuard\WmiPrvSE.exe	90125421267c6f2a55fb1566eac89528.exe
File created	C:\Windows\System32\wbem\Win32_DeviceGuard\24dbde2999530ef5fd907494bc374d663924116c	90125421267c6f2a55fb1566eac89528.exe
File created	C:\Windows\System32\mfc110u\RuntimeBroker.exe	90125421267c6f2a55fb1566eac89528.exe

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

System Information Discovery
T1082

Creates scheduled task(s) 1 TTPs 4 IoCs

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

persistence

Scheduled Task/Job

T1053

pid	Process
1844	schtasks.exe
2648	schtasks.exe
1872	schtasks.exe
1216	schtasks.exe

Modifies registry class 1 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-996941297-2279405024-2328152752-1000_Classes\Local Settings	90125421267c6f2a55fb1566eac89528.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
1568	90125421267c6f2a55fb1566eac89528.exe
2396	winlogon.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	1568	90125421267c6f2a55fb1566eac89528.exe
Token: SeDebugPrivilege	2396	winlogon.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 1568 wrote to memory of 4460	1568	90125421267c6f2a55fb1566eac89528.exe	90
PID 1568 wrote to memory of 4460	1568	90125421267c6f2a55fb1566eac89528.exe	90
PID 4460 wrote to memory of 5084	4460	cmd.exe	91
PID 4460 wrote to memory of 5084	4460	cmd.exe	91
PID 4460 wrote to memory of 2400	4460	cmd.exe	92
PID 4460 wrote to memory of 2400	4460	cmd.exe	92
PID 4460 wrote to memory of 2396	4460	cmd.exe	96
PID 4460 wrote to memory of 2396	4460	cmd.exe	96

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\90125421267c6f2a55fb1566eac89528.exe
"C:\Users\Admin\AppData\Local\Temp\90125421267c6f2a55fb1566eac89528.exe"
1⤵
- Checks computer location settings
- Adds Run key to start application
- Drops file in System32 directory
- Modifies registry class
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1568
- C:\Windows\System32\cmd.exe
  "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\5r7ocr3r92.bat"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:4460
- - C:\Windows\system32\chcp.com
    chcp 65001
    3⤵
    PID:5084
- - C:\Windows\system32\w32tm.exe
    w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
    3⤵
    PID:2400
- - C:\Documents and Settings\winlogon.exe
    "C:\Documents and Settings\winlogon.exe"
    3⤵
    - Executes dropped EXE
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:2396

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "RuntimeBroker" /sc ONLOGON /tr "'C:\Windows\System32\mfc110u\RuntimeBroker.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1872

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "winlogon" /sc ONLOGON /tr "'C:\Documents and Settings\winlogon.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1216

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "SppExtComObj" /sc ONLOGON /tr "'C:\Documents and Settings\SppExtComObj.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:1844

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "WmiPrvSE" /sc ONLOGON /tr "'C:\Windows\System32\wbem\Win32_DeviceGuard\WmiPrvSE.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Creates scheduled task(s)
PID:2648

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Persistence

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

Scheduled Task/Job

Privilege Escalation

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

Scheduled Task/Job

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

2

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\5r7ocr3r92.bat

Filesize
254B

MD5
165c776b2d15c34e5c22a0a14c6f3668

SHA1
3a57424e911bc687f515e75c3f7c4aedc67f0b13

SHA256
ed263f4965f873a7e4f10cff09ecf446914ba2a845532125b93ca7d55114af40

SHA512
1cafe361320f1ad42b7ea446edf9927bb9e8809684e3492a76888d2968282c1062babb01d04d673ac705076c5c3fd2c4aebfc07f634c7d3bce216fa4b65a3049

Download Submit
C:\Users\winlogon.exe

Filesize
1.1MB

MD5
90125421267c6f2a55fb1566eac89528

SHA1
eb56f971b495461dce763a4680b96c4e07d5a1b5

SHA256
1e9b61bacadec88ed81039e5551de06d39f558694e5756bbe7aa92d46ba488a5

SHA512
e36d7cccf5c4e7aa134a922e7d5b735cc4ab5094dd4cdb2a4407c33934459871b412c7f8d4c527d75f04535ca592fd1a354a718925ef7a21a6a28e2b02d58d6f

Download Submit
memory/1568-0-0x0000000000A00000-0x0000000000B22000-memory.dmp

Filesize
1.1MB

Download
memory/1568-1-0x00007FFDEF7E0000-0x00007FFDF02A1000-memory.dmp

Filesize
10.8MB

Download
memory/1568-2-0x000000001B940000-0x000000001B950000-memory.dmp

Filesize
64KB

Download
memory/1568-17-0x00007FFDEF7E0000-0x00007FFDF02A1000-memory.dmp

Filesize
10.8MB

Download
memory/2396-22-0x000000001B6B0000-0x000000001B6C0000-memory.dmp

Filesize
64KB

Download
memory/2396-21-0x00007FFDEF490000-0x00007FFDEFF51000-memory.dmp

Filesize
10.8MB

Download
memory/2396-23-0x0000000002A80000-0x0000000002A8A000-memory.dmp

Filesize
40KB

Download
memory/2396-25-0x00007FFDEF490000-0x00007FFDEFF51000-memory.dmp

Filesize
10.8MB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads