dcrat | f395305daac1c6e8fd577b85bc9132b5358c9e4c4b818b61f76d50d2477a3906

General

Target
DCRatBuild.exe
Size 1.1MB
Sample241123-bkh6lsznap
SHA256 f395305daac1c6e8fd577b85bc9132b5358c9e4c4b818b61f76d50d2477a3906
MD5 a92e55e04cc2026f53c97bdf0e91f6ba
SHA1 a31af958d3f885e0f55465acc214bdb0d56e672f
SHA512 441ca291ccc66f16b5252d65c23fb9f0a57f242ca35f196f41175e2c4d3adc436b026111b79fb4c77db9dbe6370e837133c1d02e571730831293e0a1ffeb95a9
SSDEEP 24576:U2G/nvxW3Ww0t43eblFYt2e9esxtDyVjD7D1NauFd3YP+ow7d:UbA3042rejxtDydhcQ
MD5 SHA1 SHA512 SSDEEP

Score

10^/10

dcrat discovery infostealer 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

Process spawned unexpected child process 9 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	3552	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2028	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4952	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	1776	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4308	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	2740	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4544	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	3372	3404	schtasks.exe	86
Parent C:\Windows\system32\wbem\wmiprvse.exe is not expected to spawn this process	4856	3404	schtasks.exe	86

DCRat payload 2 IoCs

Detects payload of DCRat, commonly dropped by NSIS installers.

rat

resource	yara_rule
behavioral2/files/0x000a000000023b88-10.dat	dcrat
behavioral2/memory/2792-13-0x0000000000A70000-0x0000000000B46000-memory.dmp	dcrat

Checks computer location settings 2 TTPs 3 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-1-5-21-3227495264-2217614367-4027411560-1000\Control Panel\International\Geo\Nation	DCRatBuild.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3227495264-2217614367-4027411560-1000\Control Panel\International\Geo\Nation	WScript.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3227495264-2217614367-4027411560-1000\Control Panel\International\Geo\Nation	portperf.exe

Executes dropped EXE 2 IoCs

pid	Process
2792	portperf.exe
1840	RuntimeBroker.exe

Drops file in Program Files directory 2 IoCs

description	ioc	Process
File created	C:\Program Files\Common Files\RuntimeBroker.exe	portperf.exe
File created	C:\Program Files\Common Files\9e8d7a4ca61bd9	portperf.exe

Drops file in Windows directory 5 IoCs

description	ioc	Process
File created	C:\Windows\GameBarPresenceWriter\55b276f4edf653	portperf.exe
File created	C:\Windows\L2Schemas\csrss.exe	portperf.exe
File opened for modification	C:\Windows\L2Schemas\csrss.exe	portperf.exe
File created	C:\Windows\L2Schemas\886983d96e3d3e	portperf.exe
File created	C:\Windows\GameBarPresenceWriter\StartMenuExperienceHost.exe	portperf.exe

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

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 3 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	DCRatBuild.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	WScript.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe

Modifies registry class 1 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-3227495264-2217614367-4027411560-1000_Classes\Local Settings	DCRatBuild.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

pid	Process
1776	schtasks.exe
2740	schtasks.exe
3372	schtasks.exe
3552	schtasks.exe
2028	schtasks.exe
4952	schtasks.exe
4308	schtasks.exe
4544	schtasks.exe
4856	schtasks.exe

Suspicious behavior: EnumeratesProcesses 10 IoCs

pid	Process
2792	portperf.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe
1840	RuntimeBroker.exe

Suspicious behavior: GetForegroundWindowSpam 1 IoCs

pid	Process
1840	RuntimeBroker.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2792	portperf.exe
Token: SeDebugPrivilege	1840	RuntimeBroker.exe

Suspicious use of WriteProcessMemory 10 IoCs

description	pid	Process	procid_target
PID 3976 wrote to memory of 4868	3976	DCRatBuild.exe	82
PID 3976 wrote to memory of 4868	3976	DCRatBuild.exe	82
PID 3976 wrote to memory of 4868	3976	DCRatBuild.exe	82
PID 4868 wrote to memory of 4500	4868	WScript.exe	87
PID 4868 wrote to memory of 4500	4868	WScript.exe	87
PID 4868 wrote to memory of 4500	4868	WScript.exe	87
PID 4500 wrote to memory of 2792	4500	cmd.exe	89
PID 4500 wrote to memory of 2792	4500	cmd.exe	89
PID 2792 wrote to memory of 1840	2792	portperf.exe	99
PID 2792 wrote to memory of 1840	2792	portperf.exe	99

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\DCRatBuild.exe
"C:\Users\Admin\AppData\Local\Temp\DCRatBuild.exe"
1⤵
- Checks computer location settings
- System Location Discovery: System Language Discovery
- Modifies registry class
- Suspicious use of WriteProcessMemory
PID:3976
- C:\Windows\SysWOW64\WScript.exe
  "C:\Windows\System32\WScript.exe" "C:\ChainBlocksurrogateagentFont\IQYI1ZQqki4.vbe"
  2⤵
  - Checks computer location settings
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:4868
- - C:\Windows\SysWOW64\cmd.exe
    C:\Windows\system32\cmd.exe /c ""C:\ChainBlocksurrogateagentFont\qVwtNBtq7doCC7qZCII8cJUJd.bat" "
    3⤵
    - System Location Discovery: System Language Discovery
    - Suspicious use of WriteProcessMemory
    PID:4500
  - - C:\ChainBlocksurrogateagentFont\portperf.exe
      "C:\ChainBlocksurrogateagentFont\portperf.exe"
      4⤵
      Checks computer location settings
      Executes dropped EXE
      Drops file in Program Files directory
      Drops file in Windows directory
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      Suspicious use of WriteProcessMemory
      PID:2792
    - - C:\Program Files\Common Files\RuntimeBroker.exe
        
        "C:\Program Files\Common Files\RuntimeBroker.exe"
        5⤵
        Executes dropped EXE
        Suspicious behavior: EnumeratesProcesses
        Suspicious behavior: GetForegroundWindowSpam
        Suspicious use of AdjustPrivilegeToken
        
        PID:1840

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 13 /tr "'C:\Windows\L2Schemas\csrss.exe'" /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:3552

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrss" /sc ONLOGON /tr "'C:\Windows\L2Schemas\csrss.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2028

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "csrssc" /sc MINUTE /mo 11 /tr "'C:\Windows\L2Schemas\csrss.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4952

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "StartMenuExperienceHostS" /sc MINUTE /mo 13 /tr "'C:\Windows\GameBarPresenceWriter\StartMenuExperienceHost.exe'" /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:1776

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "StartMenuExperienceHost" /sc ONLOGON /tr "'C:\Windows\GameBarPresenceWriter\StartMenuExperienceHost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4308

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "StartMenuExperienceHostS" /sc MINUTE /mo 10 /tr "'C:\Windows\GameBarPresenceWriter\StartMenuExperienceHost.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:2740

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "RuntimeBrokerR" /sc MINUTE /mo 10 /tr "'C:\Program Files\Common Files\RuntimeBroker.exe'" /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4544

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "RuntimeBroker" /sc ONLOGON /tr "'C:\Program Files\Common Files\RuntimeBroker.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:3372

C:\Windows\system32\schtasks.exe
schtasks.exe /create /tn "RuntimeBrokerR" /sc MINUTE /mo 8 /tr "'C:\Program Files\Common Files\RuntimeBroker.exe'" /rl HIGHEST /f
1⤵
- Process spawned unexpected child process
- Scheduled Task/Job: Scheduled Task
PID:4856

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Credential Access

Discovery

Query Registry

2

T1012

System Information Discovery

2

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

IQYI1ZQqki4.vbe

Path C:\ChainBlocksurrogateagentFont\IQYI1ZQqki4.vbe
Size 230B
SHA256 01543751a00db2bbbaaf366aa712303363c484c1f9970ae04857f6703473a5e2
MD5 b3e0630669e9f81b3e57048e6af1e015
SHA1 650473dc5a9144a544fb53af84ef4fc8e0a72320
SHA512 ac7e7fdf1fb92273a08e030d9f4b407faa4b759c85932a7a2463df92f83f5bb7b596b9d8b2e0acea1a20305903f4e425e7a82edf4f12c9ca60c56f67bca1236f
MD5 SHA1 SHA512

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portperf.exe

Path C:\ChainBlocksurrogateagentFont\portperf.exe
Size 829KB
SHA256 4b6302643800dafe4629960e243ba26663f8510c42f4eaf656b1cc510406e408
MD5 a054982f7e12c1f491eccd25d9c1b5d7
SHA1 b3c78b1c7c8a95486db06e39f56910d0f3e90996
SHA512 d57be5af22f21e7c20d330f5714ddcf1936152e3d9bd2254c1a2c83f420bfe183ae204c871b1ce2d8f5361a1661afbe39a9b5bec12fb00195a8c0b967977a925
SSDEEP 24576:b3eblFYt2e9esxtDyVjD7D1NauFd3YP+ow7:b2rejxtDydhc
MD5 SHA1 SHA512 SSDEEP

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qVwtNBtq7doCC7qZCII8cJUJd.bat

Path C:\ChainBlocksurrogateagentFont\qVwtNBtq7doCC7qZCII8cJUJd.bat
Size 46B
SHA256 5f60a9046ff7978e0518ad160509409a8818dbea53faa79c5d93364dd8d70f95
MD5 00afe3a3fcc7952dfadc97502a3aecac
SHA1 6b7e7835cd437e437c91ad91255efe5c8f24c0f4
SHA512 9af6ecb3ff68382c633e640d29e86d17597faa2ab712f75697bdf98596c6b17146991ec88fd94df8c65a8fa6ae60e763a66747cf0be4ae37d60beb1e8ff87cc3
MD5 SHA1 SHA512

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memory/2792-12-0x00007FF802673000-0x00007FF802675000-memory.dmp

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memory/2792-13-0x0000000000A70000-0x0000000000B46000-memory.dmp

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Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads