dcrat | f014b4dd1600fb5ecd92de55165573415c2d7ee184a4f70f2f975ee7909150f6

General

Target

Bridgewebsvc.exe
Size

828KB
MD5

fddea23e803e9e5de212e4c0475c8f93
SHA1

c4426bf36ce54917155da2bfbec1508c5a799664
SHA256

f014b4dd1600fb5ecd92de55165573415c2d7ee184a4f70f2f975ee7909150f6
SHA512

05459fc75998ee306e8de7e544aaf744e5c6e1930dcb7e02b94a566a7ad6e874a9fe50a78a1da50b4e7110282e49353f8ced586117d772b600b84d09ee070591
SSDEEP

12288:F+RK+UfXST5/rKMyFckcb8M41AT0z/GAFPz3DhsHxrofdV:5STuMMATKPTVgxr4

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 3 IoCs

persistence

Winlogon Helper DLL

T1547.004

Modify Registry

T1112

Processes:

Bridgewebsvc.exe

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\DigitalLocker\\en-US\\backgroundTaskHost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\DigitalLocker\\en-US\\backgroundTaskHost.exe\", \"C:\\Program Files (x86)\\Windows Photo Viewer\\uk-UA\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\Windows\\DigitalLocker\\en-US\\backgroundTaskHost.exe\", \"C:\\Program Files (x86)\\Windows Photo Viewer\\uk-UA\\dllhost.exe\", \"C:\\Recovery\\WindowsRE\\backgroundTaskHost.exe\""	Bridgewebsvc.exe

Process spawned unexpected child process 9 IoCs

This typically indicates the parent process was compromised via an exploit or macro.

Processes:

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

description	pid	pid_target	Process	procid_target
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1744	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4436	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	5064	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	3736	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2932	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2096	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4372	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	132	448	schtasks.exe	79
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1108	448	schtasks.exe	79

DCRat payload 2 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

Processes:

resource	yara_rule
behavioral1/memory/3480-1-0x0000000000BA0000-0x0000000000C76000-memory.dmp	dcrat
behavioral1/files/0x001c00000002ab59-17.dat	dcrat

Executes dropped EXE 1 IoCs

Processes:

backgroundTaskHost.exe

pid	Process
664	backgroundTaskHost.exe

Adds Run key to start application 2 TTPs 6 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

Processes:

Bridgewebsvc.exe

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-1537126222-899333903-2037027349-1000\Software\Microsoft\Windows\CurrentVersion\Run\backgroundTaskHost = "\"C:\\Windows\\DigitalLocker\\en-US\\backgroundTaskHost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\backgroundTaskHost = "\"C:\\Windows\\DigitalLocker\\en-US\\backgroundTaskHost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1537126222-899333903-2037027349-1000\Software\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Program Files (x86)\\Windows Photo Viewer\\uk-UA\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\dllhost = "\"C:\\Program Files (x86)\\Windows Photo Viewer\\uk-UA\\dllhost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1537126222-899333903-2037027349-1000\Software\Microsoft\Windows\CurrentVersion\Run\backgroundTaskHost = "\"C:\\Recovery\\WindowsRE\\backgroundTaskHost.exe\""	Bridgewebsvc.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\backgroundTaskHost = "\"C:\\Recovery\\WindowsRE\\backgroundTaskHost.exe\""	Bridgewebsvc.exe

Drops file in Program Files directory 3 IoCs

Processes:

Bridgewebsvc.exe

description	ioc	Process
File created	C:\Program Files\WindowsApps\Microsoft.Paint_10.2104.17.0_neutral_split.scale-100_8wekyb3d8bbwe\microsoft.system.package.metadata\sppsvc.exe	Bridgewebsvc.exe
File created	C:\Program Files (x86)\Windows Photo Viewer\uk-UA\dllhost.exe	Bridgewebsvc.exe
File created	C:\Program Files (x86)\Windows Photo Viewer\uk-UA\5940a34987c991	Bridgewebsvc.exe

Drops file in Windows directory 3 IoCs

Processes:

Bridgewebsvc.exe

description	ioc	Process
File created	C:\Windows\DigitalLocker\en-US\backgroundTaskHost.exe	Bridgewebsvc.exe
File opened for modification	C:\Windows\DigitalLocker\en-US\backgroundTaskHost.exe	Bridgewebsvc.exe
File created	C:\Windows\DigitalLocker\en-US\eddb19405b7ce1	Bridgewebsvc.exe

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

System Information Discovery
T1082

Modifies registry class 1 IoCs

Processes:

Bridgewebsvc.exe

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-1537126222-899333903-2037027349-1000_Classes\Local Settings	Bridgewebsvc.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 9 IoCs

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

persistence execution

Scheduled Task

T1053.005

Processes:

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

pid	Process
1744	schtasks.exe
5064	schtasks.exe
2932	schtasks.exe
2096	schtasks.exe
132	schtasks.exe
4436	schtasks.exe
3736	schtasks.exe
4372	schtasks.exe
1108	schtasks.exe

Suspicious behavior: EnumeratesProcesses 4 IoCs

Processes:

Bridgewebsvc.exebackgroundTaskHost.exe

pid	Process
3480	Bridgewebsvc.exe
3480	Bridgewebsvc.exe
3480	Bridgewebsvc.exe
664	backgroundTaskHost.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

Bridgewebsvc.exebackgroundTaskHost.exe

description	pid	Process
Token: SeDebugPrivilege	3480	Bridgewebsvc.exe
Token: SeDebugPrivilege	664	backgroundTaskHost.exe

Suspicious use of WriteProcessMemory 6 IoCs

Processes:

Bridgewebsvc.execmd.exe

description	pid	Process	procid_target
PID 3480 wrote to memory of 3820	3480	Bridgewebsvc.exe	89
PID 3480 wrote to memory of 3820	3480	Bridgewebsvc.exe	89
PID 3820 wrote to memory of 732	3820	cmd.exe	91
PID 3820 wrote to memory of 732	3820	cmd.exe	91
PID 3820 wrote to memory of 664	3820	cmd.exe	93
PID 3820 wrote to memory of 664	3820	cmd.exe	93

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\Bridgewebsvc.exe
"C:\Users\Admin\AppData\Local\Temp\Bridgewebsvc.exe"
1⤵
- Modifies WinLogon for persistence
- Adds Run key to start application
- Drops file in Program Files directory
- Drops file in Windows directory
- Modifies registry class
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:3480
- C:\Windows\System32\cmd.exe
  "C:\Windows\System32\cmd.exe" /C "C:\Users\Admin\AppData\Local\Temp\uOviiU4MXS.bat"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:3820
- - C:\Windows\system32\w32tm.exe
    w32tm /stripchart /computer:localhost /period:5 /dataonly /samples:2
    3⤵
    PID:732
- - C:\Recovery\WindowsRE\backgroundTaskHost.exe
    "C:\Recovery\WindowsRE\backgroundTaskHost.exe"
    3⤵
    - Executes dropped EXE
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:664

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 12 /tr "'C:\Windows\DigitalLocker\en-US\backgroundTaskHost.exe'" /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1744

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "backgroundTaskHost" /sc ONLOGON /tr "'C:\Windows\DigitalLocker\en-US\backgroundTaskHost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4436

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 10 /tr "'C:\Windows\DigitalLocker\en-US\backgroundTaskHost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:5064

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhostd" /sc MINUTE /mo 8 /tr "'C:\Program Files (x86)\Windows Photo Viewer\uk-UA\dllhost.exe'" /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:3736

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhost" /sc ONLOGON /tr "'C:\Program Files (x86)\Windows Photo Viewer\uk-UA\dllhost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2932

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "dllhostd" /sc MINUTE /mo 7 /tr "'C:\Program Files (x86)\Windows Photo Viewer\uk-UA\dllhost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2096

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 14 /tr "'C:\Recovery\WindowsRE\backgroundTaskHost.exe'" /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4372

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "backgroundTaskHost" /sc ONLOGON /tr "'C:\Recovery\WindowsRE\backgroundTaskHost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:132

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "backgroundTaskHostb" /sc MINUTE /mo 6 /tr "'C:\Recovery\WindowsRE\backgroundTaskHost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1108

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:\Recovery\WindowsRE\backgroundTaskHost.exe

Filesize
828KB

MD5
fddea23e803e9e5de212e4c0475c8f93

SHA1
c4426bf36ce54917155da2bfbec1508c5a799664

SHA256
f014b4dd1600fb5ecd92de55165573415c2d7ee184a4f70f2f975ee7909150f6

SHA512
05459fc75998ee306e8de7e544aaf744e5c6e1930dcb7e02b94a566a7ad6e874a9fe50a78a1da50b4e7110282e49353f8ced586117d772b600b84d09ee070591

Download Submit
C:\Users\Admin\AppData\Local\Temp\uOviiU4MXS.bat

Filesize
209B

MD5
c7e9be07c0a4da46e774a084e78caa7a

SHA1
033f70a926040cb3bbd0cc176e18b18066cff4ed

SHA256
ed658d11a20c24bf795d1084e272e217c74a0dd550f7fdab29b7ffb7f2a5c273

SHA512
09a55667b1dba441757a3266721fd999d6c822b7168c8587805040f127686e8c5812900e699582ed1702659ab6e5b046e919c2ee3e1fb4d7619a402d4eafde5f

Download Submit
memory/3480-0-0x00007FFCFF133000-0x00007FFCFF135000-memory.dmp

Filesize
8KB

Download
memory/3480-1-0x0000000000BA0000-0x0000000000C76000-memory.dmp

Filesize
856KB

Download
memory/3480-2-0x00007FFCFF130000-0x00007FFCFFBF2000-memory.dmp

Filesize
10.8MB

Download
memory/3480-14-0x00007FFCFF130000-0x00007FFCFFBF2000-memory.dmp

Filesize
10.8MB

Download

Resubmissions

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads